Lake Eğirdir fills a 50-kilometre trench in the Taurus mountains, and the town that shares its name runs straight out into it — a narrow peninsula, a causeway, then an island of old fishermen's houses. Turkey's second-largest freshwater lake sits in a basin the crust pulled open and karst limestone dissolved from beneath, and for its size it is oddly shallow: about 14 metres on average, 16.5 at the deepest. Wind and light rework the surface all day, which is why people here call it the lake of seven colours. Under that surface, the fish living in the lake have been completely replaced. Pike-perch were released in 1955 to lift the catch, and the predator ate its way through the lake's own fish; the Eğirdir minnow, a small endemic species once landed by the tonne and found nowhere else, was last seen in the 1980s and declared extinct in 2013.
The causeway is the walk everyone takes: water on both sides, the ridge of Davraz behind you, and at the end Yeşilada — until 1923 a Greek village called Nis, and an island you could only reach by boat until the 1950s. Its stone and timber houses are pensions and fish restaurants now, and the fish on the plate is usually the pike-perch that rearranged the lake. Apple orchards ring the shore: Isparta province grows about a quarter of Turkey's apples, Eğirdir is its centre, and from September the lake road fills with crates. In winter the open water carries rafts of coot, pochard and grebes. The lake is under strain today — drought and irrigation have kept it close to a metre below the level the state water authority calls safe, even as it supplies Isparta's drinking water — and a recovery plan is now trying to lift it back.