Take a tour of Kalemegdan Clock Tower in Belgrade, Serbia and Montenegro -- part of the World's Greatest Attractions travel video series by GeoBeats. The Kalemegdan clock tower in Belgrade, Serbia invites visitors to enter the city's fortress of the same name. The tower stands over the Stambol Gate, a magnificent stone archway that allows passage through the fortress walls. Built in the 17th century, the clock tower has watched over Belgrade for over three hundred years. When the entire population of Belgrade used to inhabit the fortress, the clock tower was a key landmark of the city. The clock tower is also a part of the magnificent park contained within the Kalemegdan fortress. Within the fortress, visitors can visit Kalemegdan's fountains and purchase Belgradian souvenirs.