At the entrance to Kladovo, next to the Danube, stands the medieval fortress of Fetislam. It consists of two fortifications, the Great Town and the Small Town, built at different times.
The smaller town, a castle-like structure, was built in 1524 by the military commander Bali-Bey as the primary military stronghold for Suleiman the Magnificent's conquest of Europe. At that time, the fortress was called Fetislam, which comes from the Turkish words Fetih ûl - Islam, meaning "Conquest of Islam." It consists of an upper and coastal section, with total dimensions of 90 x 60 m.
This small fortress is located along the northern slopes of the Great Town.
The Great Town was formed later when the military fortress of the Small Town needed to be further secured with outer walls with moats and entrances in the form of three main gates with movable bridges. Other structures for different purposes existed within the Great Town. Over the centuries, the town was rebuilt several times. The fortresses of Fetislam, preserved in their present appearance, date back to the reign of Sultan Mahmoud II in the first half of the 20th century.
Fetislam was a military fortress and a strategically important navigation point on the Danube.
The fortress was abandoned by the Turks in 1867, along with other fortified towns in Serbia. April 26, the day the fortress was handed over to the Serbian authorities, is celebrated as Kladovo Municipality Day.