A photo of the Leaning Tower of Pisa taken in Pisa, Italy, on Aug 19, 2011. Pisa's Cathedral Square in central Pisa, Italy, is home to four of the greatest architecture styles of medieval times: the Duomo (cathedral), the Campanile (the Leaning Tower of Pisa,) the Baptistry and the Camposanto (cemetery.) Pisa's Cathedral Square was declared a UNESCO World Heritage site in 1987. [Photo/Xinhua]