Lake Tuz ( meaning 'Salt Lake'; anciently Tatta — , ) was the second largest lake in Turkey with its surface area and one of the largest hypersaline lakes in the world. It is located in the Central Anatolia Region, northeast of Konya, south-southeast of Ankara and northwest of Aksaray. In recent years, Lake Tuz has become a hotspot for tourists. In October 2021, Lake Tuz dried up completely. Geography The lake, occupying a tectonic depression in the central plateau of Turkey, is fed by two major streams, groundwater, and surface water, but has no outlet. Brackish marshes have formed where channels and streams enter the lake. Arable fields surround the lake, except in the south and southwest where extensive seasonally flooded salt-steppe occurs. For most of the year, it is very shallow (approx.). During winter part of the salt is dissolved in the fresh water that is introduced to the lake by precipitation and surface runoff (to 324‰ salinity). During the summer the lake dries up exposing an average of 30 cm thick salt layer in August. This mechanism is used as a basis for the process of the salt mines in the lake. The three mines operating in the lake produce 63% of the salt consumed in Turkey. The salt mining generates industrial activity in the region, mainly related to salt processing and refining. Geology Formation Subsidence in the Tuz Gölü Lower Basin occurred during the Upper Senonian-Lower Middle Eocene and was followed by a regression that started in the upper Eocene and continued until the end of the Oligocene. During the Upper Senonian-Lower Middle Eocene, the Tuz Gölü Lower Basin formed a single and continuous depression towards the north with the Haymana region. The Haymana Basin, which rose after the deposition of the Middle Eocene Nummulitic limestones, separated the Tuz Gölü Basin with a fault zone along the eastern edge of the Karacadağ uplift. The connection of Tuz Gölü with the north-northeast Çankırı basin occurred during the Pliocene period and continued throughout the Middle Eocene-Oligocene, when the lake basin became a graben bounded by the north-west and north-east fault zones. After the main deformation in the late Oligocene or Miocene period, local depositional basins were formed during the Neogene period, and volcanics of varying thickness and terrestrial sediments including lake limestones were deposited in these basins. The Tuz Gölü Basin has been little affected by the recent