[2] The fluvial lake developed as the flow of Karasudere, and as it came downwards from Çatalca it was blocked off and formed by the resulting sandbank it created.

A reedy, brackish salt-water lake exists between the Büyükçekmece Dam and the Marmara Sea.

[2] A historic 635 m (2,083 ft) long and 7.17 m (23.5 ft) wide multiple arch bridge, named after the Ottoman architect Mimar Sinan (1489-1588), spans the narrow opening at the bar connecting the lake to the sea.

[3] At the northern shore of the lake, Istanbul Hezarfen Airfield is situated on a peninsula.

The lake, which is not protected, was declared by BirdLife International as an Important Bird Area in 1989 for its numerous distinct and threatened waterfowl species.