Pekulney Lake is connected by channels with neighboring Lake Vaamochka to the west. The village of Meynypilgyno is located between both lakes, to the southwest of Lake Pekulney. The inner part of the lake has a fjord-like structure, with the mountains of the Ukvushvuynen Range, one of the foothills of the Koryak Mountains rising steeply from the shores of the lake's northern end, while the coast of the southern part is smooth and low. The banks are covered with tundra vegetation.