Ten kilometers from the town of Kardjali near the village of wide-Field are the ruins of the fortress Monak. A fortification was built in 12-13 centuries in the Rhodope mountains at an altitude of about 600 meters above sea level. Fortress Monak is considered one of the largest medieval Bulgarian fortresses in the Rhodope mountains and the highest-positioned. It is an area of about 5 hectares, access here is very complicated, as complicated very steep, sometimes almost vertical, rise.

Fortress Manak fulfilled an important strategic function, she was on the way to the Iron gate pass (Zelezny the gates), as well as guarding the way of access is located near the monastery of St. John the Prodrome of the medieval town (he was in the territory that today occupies a modern Kardjali). In the historical Chronicles have preserved information about the siege of the fortress by the Latins in 1206 (Fourth crusade, which culminated in the conquest of Constantinople by the crusaders). It is in the fortress Monak was crowned Emperor of the Latin Empire of Henry I of Flanders.

During the archaeological excavations discovered the ruins of the city wall, preserved part of which has a length of about 270 meters, a height of 7-8 meters, eight defensive towers with a height of 3-4 meters, and storage tanks for water. The building was built of blocks of stone, cemented with lime and sand mixture.

From the platform on which the ruins of the ancient fortress Manak offers panoramic views of the city Kardzhali and reservoir Studen kladenets.