Tower of Pisa
The Leaning Tower of Pisa is the campanile, or freestanding bell tower, of the cathedral of the Italian city of Pisa. The tower began to lean during construction in the 12th century, due to soft ground which could not properly support the structure's weight. By 1990, the tilt had reached 5.5 degrees. The structure was stabilized by remedial work between 1993 and 2001, which reduced the tilt to 3.97 degrees.
