The Roman castrum of Diana was constructed on a high cliff above the Danube called the Karataš, close to the town of Kladovo. The earliest, earthen and wooden, fortification is related to the arrival of the first military garrison to the Danube at the beginning of the 1st century. A large stone fortification (140×136 m) is associated with building activities of Emperor Trajans, and completed at the time the Sip Channel was dug up (101 AD) which eliminated the greatest obstacle to navigation of the Danube river.
In the mid-5th century, it was destroyed by the Huns, and reconstructed the 6th century by Byzantine Emperor Justinian. The fortification was also demolished to the ground at the time of the Avar and Slavic attacks at the end of the 6th and the beginning of the 7th century. Some exceptional archaeological findings (a variety of items for everyday use, marble and bronze sculptures) reveal the fact that besides its role in protecting and defending the channel, Diana also was a major economic center, with its own port and dock.
Within the fortification, a structure with an apse has been found, as well as army barracks, with the remains of the “principia” (military headquarters). Outside the walls, the existence of a religious sanctuary has been established, the remains of a martyrium and parts of a necropolis, as well as parts of a settlement which extended west of the military encampment.