Downstream from the Đerdap 1 Hydroelectric Power Plant and along the route of the modern road leading from Tekija to Kladovo, there is one of the largest and best-preserved Roman camps on the Danube – Diana. The imposing fortified city is located on a rocky, slightly elevated bank of the river, which is why it took the name Karataš or Black Stone. It covers an area of ​​3 hectares and is one of the most complex fortifications on the Danube limes. 

The construction of the fortress is related to the period of the reign of Emperor Trajan, when, in addition to numerous buildings, it was erected as one of the bases for the war against the Dacians and King Decebalus. It is assumed that the fortress was built around the year 101, when the excavations of the Sip Canal was completed, which removed the biggest obstacle to navigation on the Danube. 

During six centuries, the fortress was built and renovated, had a port and a dock for ships and was a very important economic center. It is believed that it got its final look much later, it was renovated for the first time in the 3rd century, and two new ramparts were built in the 4th century. In the 6th century, during the reign of Emperor Justinian I, the fortress was rebuilt, but soon after that period it was invaded by the Avars and Slavs, from which it did not recover. 

Diana Fortress is a stone fortification. Like many other camps throughout the Roman Empire, it was built on the same principle. Within the camp, there were important roads, headquarters buildings, barracks for soldiers, and granaries. What sets it apart from other Roman camps is the strategically important place where it was built, from where the traffic on the Danube or the Sip Canal was controlled, and not far from the camp was Pontes and the bridge over the entrance to Dacia. 

The fortress has the base of a rounded rectangle, with strong stone ramparts and towers. Four gates were arranged, one on each side, three were reinforced with semicircular towers, except for the fourth, which faced the Danube, which shows that the greatest danger to the camp was threatened from the mainland. 

Archaeological excavations so far have brought new knowledge not only about the appearance of the fortress but also about the life that took place in the camp. Based on the discovered and researched objects, as well as the found objects that are kept today in the Archaeological Museum of Đerdap in Kladovo and the Museum of Krajina in Negotin, we find out how people lived in the camp during the war and how in the days of peace. Roman historians wrote about the daily life and activities of soldiers on the border of the empire “Soldiers built ramparts, built fortifications, repaired roads and bridges, gained fitness by running and practicing or trained to be scribes, librarians, non-commissioned officers …” Many very beautiful ceramic and glass vessels found at the Diana site tell us about the way of life and diet of the soldiers and crew, as well as the weapons and tools that were in use. 

Historical sources also testify to the sufferings of the fortress. In the second half of the 4th century, during their campaign in the Balkans, the fortress was attacked and partially burned by the Goths, in the first half of the 5th century it was destroyed by the Huns, and in the 6th century after Justinian’s restoration, in the campaign of the Avars ​​and the Slavs on the Balkan Peninsula, it experienced a final collapse. 

Today, the Diana-Karatash Fortress is an archeological site of exceptional importance under the protection of the Republic of Serbia and another pearl among the Danube fortresses that, along with thirty other Roman sites, called the Danube Limes or the Border of the Roman Empire, is waiting to become part of UNESCO World Heritage.