Project for 3D Visualizing of the history of the town of Novi Sad and Petrovaradin fortress. Among most challenging subject is revealing of the true appearances of the famous fortified Cistercian Abbey of Belefons, built by Hungarian King Bella. Its remnants are hidden deep beneath later Habsburgian baroque fortress of Petrovaradin, but archaeological campaign in 2004/5 provides essential evidences of its architecture which, in combination with historical reports, allow us to reconstruct appearance of this masterpiece of Cistercian architecture.