Lake Burdur spreads west of the city, a large salty and alkaline lake with a stark, open feel. It is not a swimming lake in the usual holiday sense, and the shore can look harsh, but the water and mudflats are important for wintering birds.
The lake is best treated as a short scenic stop rather than a full outing. Bring binoculars if you have them, and do not expect the manicured waterfront of a resort town.