Tholos is an ecotourism center in Egirdir. The complex provides a unique experience in swimming, sailing, and diving combined with observation and research for visitors and locals. It consists of swimming pools, sailing & diving courses, a botanical garden, cafes, boat maintenance spaces, labs, and a small research center.

The whole complex is made of intersecting brick vaults of various sizes with timber structure double façades. Construction materials are made of slime from the bottom of the lake to create a sustainable complex. Also, passive systems such as cross ventilation, trombe wall, ventilated roofs, and bioswale systems are used in the buildings.