http://www.veljkomilkovic.com/OtvrdjaviEng.htmPETROVARADIN FORTRESS

Picture 2. Novi Sad and Petrovaradin, detail from the map dated 1698

Picture 4. The Petrovaradin fortress in three centuries: 1- Inzel ditch / the island fortress sunk in the 19th century; 2- Wasserstadt - the Water City; 3- The Upper fortress on the Petrovaradin rock with dominant buildings; 4- Hornwerk / bicorn bastion with a Kronenwerk; 5 - Extended facility / unfinished ditches, disappeared in the earthquake of 1726; 6 - Bridgehead on the left bank of the Danube, destroyed around 1928