Diana castrum was built in 100-101 AD in Kladovo, Serbia. Diana Fortress is located on cliffs above the Danube in the Karatas archaeological site near Kladovo. The main buildings were built on a strategic location overlooking the Danube.
Further modifications were made at the end of the 3rd and beginning of the 4th century when additional towers were added towards the river for extra defence towards the Danube shores.
At the mid 4th century the fort was damaged and in 530 AD rebuilt by Roman Emperor Justinian.
Besides the military buildings, a sacrificial necropolis and civilian settlement is located within the walls.
In 1983, Diana Fortress was added to the Serbian Archaeological Sites of Exceptional Importance list.