General

The Tower of Pisa is actually the bell tower of the cathedral in Pisa. But right after it's construction started, in 1174, as a result of the poor swampy soil beneath, has started to lean. Today, one side is five metres (16feet) closer to the ground than the other. The tower is 55.86 metres (183.27 feet) high and it is leaned at an angle of 5.5 degrees. Due to restoration works between 1990 and 2001 the tower now leans at an angle of only 3.99 degrees.

The construction of the tower was very complex, and it was built in three stages, over a period of 177 years. After the construction progressed to the third floor, in 1178, the tower began to sank. After this, the construction was stopped for almost 100 years, as the people of Pisa were engaged in battles with Genoa, Florence and Luca. This allowed time for the soil to settle down, or otherwise the tower would have certainly crashed. In order to compensate for the lean, the engineers built higher floors with one side taller than the other. This made the tower begin to lean in the other direction.