Chott el Djerid dry Salt Lake. The largest, the Chott el Djerid, covers 5000 km2 at the most, and lies in the middle of Tunisia, close to the Algerian border. Chott el Djerid was some thousand years ago part of the Mediterranean Sea. The part on the eastern side is called Chott el Fejej. At times, parts of it appear in various shades of white, green and purple.