Insuyu Cave is a show cave situated near Burdur in southwestern Turkey. Being over 500 m in length, it was discovered in 1952 and opened to public in 1965. A second cave beyond the show cave was later discovered.
Show cave length: 597 m (1,959 ft)
Number of visitors: 65,378 (2011)
Location: Burdur, Turkey
The Insuyu cave is a natural cavern formed by the dissolving of limestone rock by the seepage of rainwater through natural cracks from the surface. Rainwater takes carbondixide from the air and forms carbonic acid. This acidic rain water seeps into the caverns, dissolving the limestone and thus enlarging the cavern.
The age of the caverns are not precisely determined, although it is assumed to be between 500.000 and 1.000.000 years, as most of the other carstic cave systems in Turkey are.