The fortress is situated on large cliff hanging over the left bank of the Assenitsa River, 3 kilometers south of Assenovgrad. The original stronghold on this site was build by the Thracians in 5th - 4th c.B.C and quickly attained strategic significance. Under the reign of Tsar Ivan Assen II, the existing stronghold was expanded into Fortress with its own military forces and administration. The fortress was conquered by the Byzantines under his heirs, but in 1344 under Tsar Ivan Alexander the Bulgarians regained it. During the Ottoman invasion in 14th century it was almost completely destroyed.
The excavation work revealed remains of the fortress walls, the castle of the feudal lord and three water reservoirs. The only preserved and most remarkable building in the fortress is a 13th - century church called St Mary. It is for the exquisite architecture, plastic decoration of the south facade and fragments of the unique 14th - century murals that the church is said to be one of the best examples of medieval architecture in Bulgaria. After the restoration work was completed in 1991, it is now an active Orthodox church.
