Cal CaveA small stream that is active throughout the year is flowing from inside the cave, which is also considered as one of the longest caves in the world. There is a rock fort on the cave and a castle block on the cave. There is a historical castle on Doğankaya. Cal Cave, Trabzon Province 5 km from Düzköy District. 1050 m from the sea on the southwest. It is located in Çal köy Mahallesi which is located at altitude. The entrance of the cave on the underground water channel exit varies widely as it travels along with it being wide. The cave is divided into two branches at 200 m. The left hand arm is about 150 m. Length. In the room at the end of this column there is an active chimney of the water coming from the pit. The accessible part of the right arm is about 400 m. A small lake and cascade are located at about 60.m. Cal Cave limestone is formed due to fracture (fault) systems in the blocks. Çalköy Cave is 4 km long and can be visited by a first kilometer. In 2003, 30-50 thousand tourists visit the cave which is opened to tourism and has caves with creeks, waterfalls, lakes, water chutes, stalactites, stalagmites and travertines. Surrounded by mixed spruce forests, Doğankayası, Camili Nature Park and Cal Cave with daily rest facilities, the magnificent natural forms of stalactites and stalagmites attract tourists from all seasons with its deep water, waterfalls and lakes that reach to 1.5 meters depth from time to time.