Ervynaygytgyn

Ervynaygytgyn (Эрвынайгытгын; Ирвынейгытгын) is a freshwater lake in Iultinsky District, Chukotka Autonomous Okrug, Russian Federation. It has an area of about 15 km2 (13.1 km2).

There are no permanent settlements on the shores of the lake.

The name of the lake in Chukot means "a lake near a sharp mountain."

Geography
Ervynaygytgyn is located in the Chukotka Mountains of the Chukotka Peninsula, about 30 km southwest of lake Ekityki and 35 km to the north of Yanranaygytgyn. The lake is elongated and stretches roughly from NW to SE. The western section is broad and the lake narrows towards its eastern end.

The lake lies in a swampy intermontane basin with a number of rivers flowing into it. The largest is the 106 km long Irvyneyveem, a tributary of the Amguema. It flows across the lake, entering it from the NW and flowing out of it from the southeastern end. Ervynaygytgyn freezes in the first half of September and stays under ice until June.