Inder Lake, Salt lake in Atyrau Province, Kazakhstan

Inder Lake is a closed salt lake in the northern part of Atyrau Province, Kazakhstan, lying 10 km east of the Ural River. It is round, slightly elongated from northwest to southeast, with a diameter of 10 to 13.5 km and a surface area of about 110 km². It has no surface inflows and is fed by saline springs through clay layers and by spring meltwater and rain. The Inder Mountains rise along its northern and northeastern shores.

Russian geologists took an interest in the lake and its surroundings in the 19th century, when it was thought the lake could supply all of Russia's salt; its inaccessibility prevented that. At the time it dried out completely by the end of the warm season, leaving a salt-covered floor. Salt has been mined from the lake, and its clays are used for medical purposes.

The lake's Russian and Kazakh names, Inder and Inderskoye ozero, come from the Inder Mountains on its northern and northeastern shores, and the nearby town of Inderbor takes its name from the same root. Russian researchers who surveyed the lake in the 19th century gave its name to the plant Eremurus inderiensis, first found here, and to the mineral inderite.

The lake has no surface inflows and no road access described in the sources; the nearest settlement is Inderbor, an urban-type settlement and district centre, about 10 km to the north-west. The northern and north-eastern shores are bordered by the Inder Mountains. The lake is fed by saline springs through clay beds plus meltwater and rain in spring, and in the 19th century it dried out completely by the end of the warm season, leaving a salt-covered floor.

The lake and the boron and salt deposits near its shore are the type locality for seven minerals described by 2021: hydroboracite, inderborite, inderite, kurgantaite, kurnakovite, preobrazhenskite and volkovskite. Russian researchers also first found the plant Eremurus inderiensis here in the 19th century.