There's no escaping the Leaning Tower in Pisa. The medieval bell tower is one of the world's most familiar images and yet its beauty still comes as a surprise, set in chessboard formation alongside the Duomo and baptistery on the manicured grass of the Campo dei Miracoli - the "Field of Miracles" - where most of the buildings belong to the city's "Golden Age" in the twelfth and thirteenth centuries, when Pisa, then still a port, was one of the great Mediterranean powers.Perhaps the strangest thing about the Leaning Tower, begun in 1173, is that it has always tilted; subsidence disrupted the foundations when it had reached just three of its eight storeys. For the next 180 years a succession of architects were brought in to try and correct the tilt, until around 1350 Tomasso di Andrea da Pontedera accepted the angle and completed the tower.