Iskanderkul (Russian: Искандеркуль; Tajik: Искандаркӯл) is a mountain lake of glacial origin in Tajikistan's Sughd Province.

Triangular in shape, it has a surface area of 3.4 square kilometres (1.3 sq mi) and is up to 72 metres (236 ft) deep.

The first one states it used to be a location the inhabitants of which resisted Alexander's rule, and in fury, the king ordered to divert a river and annihilate them.

[3][4] A 300 square kilometres (120 sq mi) tract of land including the lake and surrounding mountains has been designated a nature reserve.

These include Himalayan snowcocks, saker falcons, cinereous vultures, yellow-billed choughs, Hume's larks, sulphur-bellied warblers, wallcreepers, Himalayan rubythroats, white-winged redstarts, white-winged snowfinches, alpine accentors, rufous-streaked accentors, brown accentors, water pipits, fire-fronted serins, plain mountain finches, crimson-winged finches, red-mantled rosefinches and white-winged grosbeaks.