Idlidlya – a small rocky island in the Chukchi Sea, Chukotka Autonomous Okrug, Russia. It is located 3–4 km from the Chukchi Peninsula against Maaminilgyn Lagoon. It is composed of massive gray granites. The northern part of the island lies higher and a sheer abrasive cliff breaks it by the sea. The island is 1 km long. On its shore there is Neshkan, a tiny Chukchi village. This island is of a particular importance for local ecologic observations, especially on species composition.