The Cave of (Big) Psistraki is a precipice located at an altitude of 950m, in the area of Evdomos and in the area of the village Gonies. Its total depth reaches 140m and has a length of approximately 90m. From its small entrance a 60 meter trench descends to the bottom, with a loft in the middle. Then a room of 25x15m is formed and then follows a longer, 50m long, with very impressive stalagmites, large gours, curtains and a beautiful pond. This lake overflows into a 90m deep pothole ending into a small room.