The rocky massif above the town of Smolyan called Kaleto is a part of the system of fortress structures, which are located on other neighboring peaks in the Rhodopes, such as those above the village of Podvis, the town of Rudozem, the village of Koshnitsa and others. From the top above the fortress there is a beautiful view of the neighboring cliffs and the town of Smolyan.
The most significant, however, is the Kaleto near Smolyan. It dates back to late antiquity and its purpose was to guard a settlement and religious centre in the mountains. It had an ideal contact with Momchil Fortress and Koznik above Rudozem. The area of the fortress is about 5 hectares, with its southern fortification wall fully exposed. Its length is 38 metres and its height is preserved to 2.5 metres.