4. Avala Tower Belgrade
The tallest structure in Serbia and the highest tower on the Balkan Peninsula, at 204 meters, Avala observation deck is the perfect place to get a bird'-eye view of Serbia's capital city. But the experience is far more than just the view. Built in 1965, the tower was demolished during the 1999 NATO bombing, then reconstructed in 2010. Today it features a 'gratitude boulevard's that displays 105 cement prints of those who helped with the reconstruction, but also top-notch facilities for visitors, from an elf village for the little ones to shopping and dining venues.