The early Byzantine fortress Kaleto is located about 2 km west of the village of Cherna Voda. The fortress sits on the right bank of the Stevreshka river, on the height between the river and its tributary, the Chanadzhiyska river (Amutlukdere).
Its main function was to guard the road which runs under the fortress wall in the north-west – south-east direction and follows the ridge of the height. The western and northern slopes are very steep and inaccessible.
From the level of the river the fortress rises to more than 150 m, and its length is about 360 m. Its shape approaches that of a regular polygon or a circle. Compared to the others, it is well preserved. In two places on the walls there are remains of towers, where the entrance to the fortress was.
