Hot Springs Throughout History

Abstract

Throughout time, natural hot springs were the reason for communities to establish settlements close to thermal water sources to use them for health benefits, recreation, and domestic purposes. An extensive exploration of the history of hot spring use has led to establishing a timeline that is to a large degree based on written accounts. The extent of the history of natural hot springs clearly demonstrates that their usage has worldwide origins, reaching back to ancient civilisations and most likely even further to prehistoric cultures. Records of early societies and their traditional use of natural hot springs as well as their remaining geoheritage are discussed and supported with examples from various countries. The use of hot springs for health and recreation is embedded in the history of all countries, where such hydrothermal resources were considered a blessing by the communities who settles in their vicinity.

5.12 Appendices

Appendix 5.1 Chronology of the Use of Hot Springs and Their Development Worldwide

The following timeline includes reference points for the plausible use of hot springs during parts of the Holocene (circa 11,700 years to current), as well as historically documented developments from a variety of countries. Included at the beginning are also believable and for many people acceptable timeframes that, while undocumented in writing, have been orally transmitted through many generations. Archaeological findings in hydrothermal areas all over the world have frequently helped to determine early users of natural hot springs. However, without written proof the prehistoric use of natural hot springs cannot be established beyond any reasonable doubt, although it can be assumed that ancient civilisations were naturally drawn to warm water sources.

Dreamtime ~60,000 BC	Australia	Dreaming stories from ancient times have transmitted the traditional knowledge about the close connection of the Aboriginal peoples with natural water sources across Australia
Neolithic age quaternary	Worldwide	Start of Neolithic times estimated at 12,000 years ago—no written records available—based on the rationale that humans were always drawn to natural hot springs, these were most likely used when and where people had the opportunity
~14,000–300 BC Jōmon Period	Japan	Possible use of hot springs for the first onsen during this period—the Dōgo Onsen is suggested by unconfirmed sources to possibly date back to as early as 14,500 BC although this remains speculation
~4000 BC	China	Hot springs are most conceivably used by early Chinese peoples based on their occurrence throughout the country
~3000–1700 BC	Indus Valley, Pakistan	The Indus Valley civilizations (e.g. Mohenjo-Daro and Harappa) are likely to have used natural hot springs that were flowing at the time. The Indus Valley includes areas abundant with hot springs, which are still utilised today, although seismic events may have relocated these sources of water over timea
~Third millennium BC	Italy	Cults and rituals related to hydrothermal manifestations are starting to appear
Third to second millennium BC	Greece	Hydrothermal by-products are extracted and traded in Greece and other Mediterranean areasb
1680–1193 BC	Anatolia, Turkey	The Hittite Empires are said to have used hot springs for recreation and therapeutic treatments
1500 BC	Greece	Ancient Greeks are visiting hot springs for hygienic purposes and start building public bathing facilities where medical conditions are also treated
1430 BC	Lipari—Sicily, Italy	Stone-lined ponds fed by hot springs were most likely used for therapeutic thermal bathing
1050–771 BC	Huaqing, China	Huaqing was the favourite hot spring destination of emperors of various dynasties and appears to have been reliably documentedc
1000–500 BC	Meso-America, Central America	The Mayan empire dates back to about 1000 BC and included Mexico in the Yucatán Peninsula, Guatemala and parts of Belize and Honduras. The abundance of hot springs in these countries leads to the assumption that the Maya used them for various purposes as they were a highly advanced society
~1000 BC	China	Hot springs are used extensively for health and recreation
~1000 BC	Western Europe	West European tradition based on worshipping of sacred and healing springs
Seventh century BC	Greece	Homer refers to thermal springs in his writings
Eighth century BC	Italy	Pompeii was founded around this time and thermal water was used to heat buildings and baths within the city
Eighth century BC	Loutraki, Greece	The thermal waters of Thermae (Loutraki) were ‘revitalised’ around this time for athletic games held at Corinth
863 BC	Bath, England	The legend of the founding of Bath tells that Bladud, father of King Lear, cured his skin condition thought to have been leprosy by immersion in the warm springs he discovered while tending to a herd of swine
Eighth to sixth century BC	Etruria, Central Italy	In northern Italy the Etruscans have used thermal bathing and geothermal by-products (750–500 BC). At this time the use of hot springs in areas under Etruscan authority is spreading systematically but with only limited development in other Mediterranean regionsd
~700 BC	Shikoku, Japan	Dōgo Onsen (Ehime Prefecture on the island of Shikoku) is one of the oldest and best known Onsen in Japan and may have been used even earlier during the Jōmon and Yayoi periods
~420 BC	Greece	Hippocrates of Kos was the first author who systematically classified the waters, including hot springs, and their distinctive properties
Fifth century BC	Greece	Hippocrates of Kos treated patients from all over the Mediterranean by using balneotherapy in his famous Asclepian Centre
Fifth century BC	Spain	Archaeological evidence indicates that the thermal springs of Archena may have been used by early Iberian settlers
Fifth to fourth century BC	Etruria, Etruscan Territories, Italy	Hot spring bathing and the use of hydrothermal by-products is widespread in Etruscan territories—methodical development of hot spring use with some initial interest by the Romans in hot spring locations in Italy for strategic purposese
Fifth to fourth century BC	Roman Republic, Italy	The Roman Republic is engaged in battles with Etruria—Roman soldiers visited hot springs for thermal bathing on military expeditions in Etruscan held territories
Fifth to fourth century BC	Greece	The benefits of hot spring bathing are mentioned by several classical Greek authors: Hippocrates, Plato and Aristotle (Tables 5.1 and 5.2)
Third century BC	İzmir, Turkey	The hot springs of Agamemnon (Balcova Termal) are mentioned in writings by Philostratos, a Greek teacher of philosophy
Third century BC	India	Megastenes, an ambassador from Greece, mentions the medicinal value of hot springs in India
Third to second century BC	Greece	Greece and other Mediterranean countries trade in geothermal by-products, e.g. kaolin, sulphur, pozzolana, etc
Third to second century BC	Etruria, Italy	After the annihilation of the Etruscans by the Romans the use of hot springs temporarily declines in the Etruscan territories—at the same time the Roman elite starts visiting hot springs
Second century BC 133 BC	Hierapolis (Pamukkale), Turkey	Hierapolis is established by Eumenes, King of Pergamon, who develops the local hot springs—in 133 BC the city is bequeathed to the Romans who build large baths near the hot springs
Second century BC	Roman Republic, Italy	Systematic development of thermal bathing culture throughout the Roman Republic – balneotherapy is becoming more prevalent in Roman society
206 BC to 220 AD	China	During the Han Dynasty salt was extracted from hot springs in the Sichuan Provincef
~120 BC	Aix les Bains, France	The Romans construct comfortable thermal baths and call them Aquae Grantianae after taking over the region
84 BC	Aedipsos, Greece	The Roman general Sulla undergoes thermal treatment after which he supports the construction of a ‘hydrotherapeutic thermal establishment’, the Thermae of Sulla
49 BC	Lisbon, Portugal	The Cassian Spas are built using natural hot mineral springs under Quinto and Lucio Cassio, who represent Julius Caesar during that timeg
First century BC	Greece	Strabo describes the main hydrothermal manifestations in the Mediterranean area
First century BC	Jordan	Jordan Valley Springs are described in the classical literature by Roman and Byzantine historians (between first century BC and sixth century AD) as having healing properties, especially for leprosy
~First century BC	Thermopolis, Wyoming, USA	Big Horn Hot Springs, known as Smoking Waters (Bah-gue-wana) by the Native American Shoshone tribe, are used for their curative value as healing waters. It is assumed that other tribes also made use of hot springs where available and that their use goes back much further than is documented
~First century BC	Palmyra, Syria	The Efca sulphur spring is used for health purposes since ‘Biblical Times’, but is thought to have either ceased to flow due to over-extractionh or has been destroyed in recent wars in the Middle East
First century BC 27 BC	Rome, Italy	The Roman Empire supersedes the Roman Republic—thermal bathing is popular with and without hot springs as the Romans have developed ways of heating their large bathhouses more efficiently—but natural hot springs are the preferred option
First century BC	Pompeii, Italy	The Forum Thermal Baths are established under the Roman dictator Lucius Cornelius Sulla (138–78 BC)
First century BC	Croatia	The first Roman thermae is built in Varaždinske Toplice and named Aquae Iasae
First century BC to third century AD	Roman Empire	Development of balneotherapy throughout the Empire—rapid spread of natural hot spring use for health and recreation
First century AD	Italy	Pliny the Elder (23–79 AD) refers to hydrothermal manifestations in his writings
43 AD	Bath, England	The initial development of the hot springs of Bath is thought to coincide with the Roman invasion of Britain in the year 43 AD
50 AD	Austria	Baden near Vienna is founded by the Romans and named Aquae
70 AD	Bath, England	The Romans build a more sophisticated bathing complex at Bath including temples and name it Aquae Sulis
81 AD	Vizela, Portugal	Roman baths are built under the reign of Titus Flavius
Second century AD	Yarmouk River Valley, Middle East	The springs at Hammat Gader are first exploited by the Romans who convert the site into thermal baths
Second century AD	Tiberias, Israel	The Romans develop the hot springs and build thermal baths
Fourth to fifth century AD	Europe	General decline of hot spring bathing—but still practiced locally at reduced levels
Fifth century AD	Caucasus, Georgia	The city of Tbilisi is founded by King Vakhtang on the site of a natural hot spring with healing powers
~476 or 480 AD	Roman Empire (West)	The fall of the western Roman Empire is initiating a rapid decline of hot spring use as a cause of immorality
552 AD	Japan	Introduction of Buddhism and purification through immersion using thermal springs
~700 AD	Ishikawa Prefecture, Japan	The Yamanaka Onsen of Kaga is founded near a temple—the historical significance is recorded on a scroll depicting the origin of Yamanaka Onseni
720 AD	Matsuyama, Japan	The Dōgo Onsen is mentioned in the Japanese chronicles Nihon Shoki (Nihongi)
765 AD	Aachen, Germany	First written record of Aachen, previously named by the Romans Aquis Villa
870 to 930 AD	Iceland	The time of Iceland’s settlement—according to the Sagas hot springs are used for washing and bathing
900 AD	Lagkadas, Greece	A thermal spa is built and offers medical services as well as recreation to its visitors
~800 to 1200 AD	Kumamoto Prefecture, Japan	The Yamaga Onsen on Kyushu Island is said to have a history of 1200 years going back to the Heian Period (794–1192)
1137 or 1175 AD	Cieplice, Poland	Cieplice Śląskie is mentioned in historical records and regarded as Poland’s first health resort. However, the legend holds that the hot spring was accidentally discovered by Prince Boleslaus the Tall [decades later] in the year 1175 AD while chasing a wounded deer, which regained its strength from the warm water
1178 AD	Budapest, Hungary	The establishment of a settlement called Felhéviz (Upper Hot Spring) is mentioned in records—descriptions also refer to a hospital being built on the site of today’s Hotel Gellért
Twelfth century AD	Budapest, Hungary	Knights of the order of St. John are curing the sick in the area of today’s Lukács Bath
1281 AD	Cieplice, Poland	Historical record of the use of hot springs by the Knights of St. John of Jerusalem to cure diseases
1294 AD	Iceland	First written account in the chronicle Oddaverjaannjáll of the original Geysir connected to a series of earthquakes during which large new hot springs appeared and others vanishedj
~Fourteenth century AD	Belgium	A health resort is founded in the city of Spa
1300s AD	New Zealand	Māori are using hot springs for healing and recreation since they colonised New Zealand between 1320 and 1350
1349 to 1350 AD	Czech Republic	According to legends the hot springs of Karlovy Vary (Karlsbad) are discovered during a deer hunt with settlements emerging close to the thermal springs
1359 to 1389 AD	Bursa, Turkey	The Ottomans build a large complex of domed baths during the reign of Sultan Murat I
Fourteenth to sixteenth century AD	Europe	Early development of spas on sites of ancient medicinal hot springs
1417 AD	Italy	Ugolino de Montecatini (1348–1425), the founder of balneotherapy in Italy, recommends the use of the mineral waters of Montecatini
1458 AD	Asan, South Korea	The Oonyang Spa is in use since the kings of the Joseon Dynasty visited the hot spring area for health and recreation
1485 AD	Portugal	Caldas da Rainha hospital is founded by Queen Leonore, who discovers natural hot springs with healing properties
Fifteenth century AD	Germany	Annual visits to hot spring therapy centres are becoming en vogue among the wealthier population
Fifteenth century AD	Budapest, Hungary	Early records about the miraculous hot springs at the site of today’s Hotel Gellért (which was built much later)
1500s AD	North America	First recorded history of European style hot spring spas in North America
1502 to 1533 AD	Peru, South America	The hot springs of Cajamarca are used by the Inca ruler Atahualpa and his court as indicated in oral historical accounts
1522 AD	Karlovy Vary (Karlsbad), Czech Republic	In the sixteenth century the water of the Mill Spring is used mainly for bathing—and around 1522 the drinking cure of Karlovy Vary is introduced
1541 AD	Arkansas, North America	The Spanish explorer Hernando deSoto is claimed to be the first European visitor of Arkansas Hot Springs, which then were named the Valley of the Vapours
1545 AD	Brazil, South America	The hot springs of Caldas Novas are first mentioned in Spanish publications
1550 AD	Peru, South America	First European (Spanish) written records of hot springs and their use in Peru
1558 to 1603 AD	Bath, England	During the Elizabethan era Bath is revived as a spa with improvements to the thermal baths and begins to attract members of the aristocracy, who spend the fashionable ‘Saison’ in Bath
1565 to 1570 AD	Budapest, Hungary	Construction of the Király Thermal Bath is started by Arslan, the Pasha of Buda
1566 AD	Budapest, Hungary	The Rudas Thermal Bath is built under Turkish occupation
Seventeenth century AD	Hainan, China (PRC)	Guantang hot springs are already known during the early part of the Qing Dynasty (1644–1911)
1697 AD	Taiwan, China (ROC)	Hot springs are first mentioned in a manuscript (Beihai Jiyou), but not fully developed until 1893
Seventeenth century AD	Europe	Hot spring spas exist throughout much of the European continent
Seventeenth century AD	China	Physicians evaluate and classify several medicinal springs
1709 AD	Japan	First Japanese medical study of hot springs
1722 AD	Caldas Novas, Brazil	Bartolomeu Bueno da Silva encounters hot springs while searching for gold, and settlers start using the thermal water
1737 AD	Belgium	A text about ‘Demonstrations on the usefulness of the Mineral Waters of Spa’ is published
1741 AD	Avéne, France	The first thermal baths are built
1776 to 1784 AD	Aix les Bains, France	The King of Sardinia, Victor Amedée II, establishes thermal baths, named the ‘Etablissement Royal des Bains’
1785 AD	Archena, Spain	King Carlos III orders the complete redevelopment of the spa town Archena, after many facilities were damaged by floods
1786 AD	Villatoya, Spain	Friar Benito Marco, a Franciscan monk from the convent of Mahora, provided one of the first testimonies proclaiming the medical significance of the waters of Villatoya together with a precise map of the springs in the region
1790 AD	New York State, North America	Saratoga Hot Springs are offering spa treatments and accommodation
1798 AD	Villatoya, Spain	The thermal spa Baños de la Concepción is mentioned in written documents
Early eighteenth century AD	Budapest, Hungary	First water analyses are carried out in Budapest on the orders of Maria Theresia (Archduchess of Austria, Queen of Hungary and Bohemia, Holy Roman Empress)
Nineteenth century AD	North America	Hot spring therapy is becoming popular
Nineteenth century AD	Furnas—São Miguel Island—Azores, Portugal	The spa resort of Furnas has become a popular tourist destination, although locals most likely used the volcanic hot springs since the Azores islands were first settled during the fifteenth and sixteenth centuries
Early 1800s AD	Austria	Baden near Vienna is redeveloping thermal bathing traditions and establishes new spa town policies
Early 1800s AD	South Africa	Europeans are visiting South Africa in search of a miracle curek
1826 AD	Hawaii, North America	An early missionary and historian, William Ellis, describes the use of a hot spring-fed crater lake in the Kapoho area
1832 AD	Hot Springs—Arkansas, North America	The area of Hot Springs becomes the first national reserve in the United States
1834 AD	Chile, South America	Jahuel Hot Springs, which is considered one of Chile’s oldest thermal centres, is visited by Charles Darwin in 1834
1851 AD	South Africa	The first research on hot springs is conducted in South Africa
1859 AD	Hanmer Springs, New Zealand (South Island)	The hot springs at Hanmer Springs are discovered by an early pioneer but were long before used by travelling Maoril
1873 AD	Namibia, Africa	The potential of the hot springs of Warmbad (Bela Bela) is discovered by white settlers, but the thermal waters were known earlier to local tribes who used it for its curative benefits
1876 AD	Uganda, Africa	The African explorer HM Stanley visits Mtagata Hot Springs in Uganda—local inhabitants appear to have used thermal springs for their curative properties (see Fig. 5.2)
1878 AD	Rotorua, New Zealand	The Priest Spring is discovered by a catholic priest, who cures his arthritis in the hot spring
1879 AD	Helidon, Australia	Initial development of the Helidon Spa in the state of Queensland
1882 AD	Banff, Canada	The Banff Hot Springs are discovered and used mainly by European visitors
1884 AD	Budapest, Hungary	The Lukács Bath Spa Hotel is built
1891 AD	Bulgaria	The first ‘Law for the preservation of mineral springs’ is enacted in Bulgaria and springs are declared a national property by law
1891 AD	Issyk-Ata, Kyrgyzstan	The Issyk-Ata sanatorium is established as a thermal health facility
1892 AD	Portugal	The first official regulation concerning the Portuguese waters resources is published
1893 AD	Matsuyama, Japan	The current main Dōgo Onsen Honkan building, a public bathhouse, is constructed to join seven original buildings together
1895 AD	Moree—New South Wales, Australia	The first bore into the Great Artesian Basin in NSW is completed with the water gaining fame for its use in Moree’s hot artesian baths, which are said to heal numerous ailments and are used for health and recreation
1895–1945	Beitou, Taiwan (ROC)	Taiwan’s hot springs are developed under Japanese occupation—opening of first hot spring resort in Beitou
Early 1900s	Kangal, Turkey	The Kangal hot springs attract initial attention when a shepherd hurt his foot, only to see it healed by the warm spring water
1911	Karlovy Vary (Karlsbad), Czech Republic	Karlovy Vary is reaching the highest number of spa guests in its history with 70,935 people undergoing a cure in the year 1911
1918	Budapest, Hungary	The Gellért Baths are established with indoor and outdoor pools
1925	Hajdúszoboszló, Hungary	Natural thermal springs with healing powers are discovered at Hajdúszoboszló while drilling for oil
1929	Bulgaria	The Bulgarian Balneological Society is set up and unites specialists from different scientific fields
1931	Japan	Japan starts to carry out more scientific research programs into hot springs
Early 1930s	Budapest, Hungary	Budapest is awarded the title ‘Spa City’ as the capital with the most healing hot springs in the world
1937	Budapest, Hungary	The first International Balneological Congress takes place in Budapest with the seat of the international Balneological Association established at the Gellért Thermal Bath
1940	North America	Most American hot spring spas and resorts went into decline around this time
1940s	Tbilisi, Georgia	Establishment of the Tbilisi Balneological Health Resort
1945	Taiwan (ROC)	Hot spring culture went into decline after the Japanese occupation ended
1970	Aix les Bains, France	Restoration and enlargement of the thermal baths
1975	Tunisia, Africa	The Tunisian Office du Thermalisme is established, located in the capital Tunis
1976	Svartsengi (near Grindavík), Iceland	The Svartsengi geothermal power station is built, which creates a large lagoon of surplus geothermal water and shortly thereafter an employee notices the healing properties of the water
1978	Bath, England	The old thermal baths are closed down and bathing is prohibited due to public health concerns over the purity of the spring water
1979	Budapest, Hungary	A daytime hospital with complex thermal bathing facilities is established at the Lukács Thermal Bath
1982	Huaqing (near Xi'an—Shaanxi Province) China	Ruins of the imperial hot spring pools in Huaqing are discovered and restored
1987	Blue Lagoon (near Grindavík), Iceland	The first public bathing facilities of the Blue Lagoon open next to the Svartsengi geothermal power station
1987	Bath, England	The city of Bath is inscribed in the UNESCO World Heritage list
1989	Karlovy Vary (Karlsbad), Czech Republic	A new era of developing balneotherapy centres starts in the Thermal Spring Valley
1994	Portugal	Forty (40) health spas throughout Portugal are using natural hot mineral springs. Of these springs, seventeen (17) are permitted by government regulation to treat dermatologic diseases
1994	Hainan, China (PRC)	The National Mineral Storage Resource Committee verifies and approves natural hot springs in Guantang as suitable for tourism and medical treatment
1995	Japan	Hospitals integrate spa medicine using volcanic hot springs
1997	Argentina, South America	After successful drilling for hot water the first thermal spa in the northeast of Argentina opens in 1997
1999	Taiwan	Hot spring culture is making a comeback due to large-scale promotion by the Taiwanese government
2004	Mývatn, Iceland	In the northeast of Iceland, the Mývatn Nature Baths (Jarðböðin við Mývatn) open
2005	Victoria, Australia	The first stage of the Peninsula Hot Springs Centre, a new development with natural hot springs, opens in the Mornington Peninsula south of Melbourne
2005	Blue Lagoon, Iceland	A new clinic for psoriasis patients opens, using natural geothermal seawater for treatment
2006	Bath, England	Opening of the new Thermae Spa Bath after years of redevelopment of the existing natural hot springs
2018	Victoria, Australia	Major expansion of the Peninsula Hot Springs in response to increasing visitor demand—further development projects are planned (Appendix 6.2)
2019	Beppu, Japan	New large hotel development—the ANA InterContinental Beppu Resort & Spa offers hot spring heritage combined with luxury accommodation
2020	Húsavík, Iceland	Opening of GeoSea, the geothermal seawater baths on the coast with views over the Arctic Ocean

1. Sources include ^aErfurt-Cooper and Cooper (2009)
2. ^bCataldi and Chiellini (1995),
3. ^cSchafer (1956)
4. ^d,eCataldi et al. (1999)
5. ^fWang (1999)
6. ^gPicoto (1996)
7. ^hWaltham (1996)
8. ⁱYamanaka Onsen (2019)
9. ^jHroarsson and Jonsson (1992)
10. ^kSpicer and Nepgen (2005)
11. ^lHanmer Springs Thermal Pools & Spa (2019)

Appendix 5.2 Hierapolis and the Travertine Terraces of Pamukkale

The original painting shows the ruins of Hierapolis, then known as Pambouk Kalesi (meaning cotton castle), which is now called Pamukkale. It was painted by Thomas Allom on the way from Laodicea circa 1838. Later reproductions were coloured in (compare image at the beginning of this chapter. Source Allom and Walsh (1838)

Appendix 5.3 Hot Spring History—Then and Now

1, 2—Caldeira das Furnas (São Miguel, Azores) c. early 1900s and the same location in 2014; 3, 4—Inside the bathhouse of Beitou (Taiwan) when it was still in use and the empty pool now; 5, 6—The hydrothermal phenomena of Beppu (Japan) then and now; 7, 8—Maruia Hot Springs (New Zealand) and the first bathing huts c. early 1900s. On the right a contemporary view of one of the new buildings

Appendix 5.4 Plan of the Roman Bath Complex in Bath, UK

A plan from December 1886 shows the excavated sections of the Roman Bath Complex in Bath, UK

Appendix 5.5 The King’s Bath in Bath, UK

1—A satirical painting titled the ‘Comforts of Bath’ by Rowlandson (1798); 2—The King’s Bath in a painting by John Nixon from 1801—both pictures include King Bladud watching over the healing waters (see Chap. 6; Fig. 6.23)

Appendix 5.6 Bad Aachen (Aix-La-Chapelle, Aquisgrana) and Burtscheid/Aachen, Germany

1—The Emperors Bath (Kaiserbad) in Aachen with floating trays for Food and wine. Source Luyken (1682) (Public Domain); 2—The Spa Park (Kurpark) in Burtscheid/Aachen. Source Unknown author (1822) (Public Domain)

Appendix 5.7 Peninsula Hot Springs, Victoria, Australia

1—The original development site of the Peninsula Hot Springs started as a horse paddock in 1997 on the Mornington Peninsula in Victoria (Australia); 2—The aerial view shows the Peninsula Hot Springs in 2019—the location is the same as the image above and has been transformed into a hot spring paradise with over sixty thermal bathing pools. In the foreground is a stage for cultural performances, which take place on a regular basis; 3, 4—the shows on the stage can be observed from the hot pools, which were built into the hillside to create a natural amphitheatre

A drawing by Joseph Latour from the nineteenth century depicts visitors at a ferruginous (chalybeate) spring in Luchon, France. Today Bagnères-de-Luchon is a fashionable health resort and famous for its thermal springs (up to 65 °C) and its Roman heritage