One of the most popular fortresses in Europe. Fortress gained special importance by organizing a music festival "Exit" on it. Another interesting things about Petrovaradin fortress are 16km of tunnels beneath it , in 4 levels, and the clock seen in the photo is specific because clock hands are reversed. Actually, the great clock hand is smaller and the smaller is big one. The reason why this watch is made like this is the visibility of the fishermen's on the Danube, so that they can easily be able to determine what time is it, even in bad weather conditions.