The level of water rises in spring and decreases in autumn. Because of cracks in the bed of the lake, the level decreases each year. In the south, near Egirdir there are 2 islands which are called Yesilada and Canada. A part of the city's population live on Yesilada. In the past, transportation used to be by boat but today the island is connected to the land.
Water is supplied by small surrounding rivers.
Freshwater fish and crawfish can be caught in the lake. There are 22 islands. On the islands and around the lake there are pelicans, cormorants, gulls and herons. It is a very beautiful Seljuk mosque which was built at the end of the 13C AD by Esrefoglu Suleyman Bey, a local ruler. The walls are made of stone but the interior is wooden and is quite different from usual mosques.