The Leaning Tower of Pisa is the campanile, or freestanding bell tower, of the cathedral of the Italian city of Pisa. It is known worldwide for the nearly four-degree lean.
Construction lasted for 344 years. It began in August 1173. The tower began to lean in 1178 once construction on the second floor began. Construction stopped two times. The first time for 100 years, and the second time in 1284.
At one point, the tower’s lean switched directions. One of the more interesting facts about the Leaning tower is the mistake. The leaning was result of a human mistake. One minor miscalculation made in the 11th century left us with an amazing tower.
This documentary explains how the little mistake shaped the tower.