The Leaning Tower of Pisa is famous for one thing, it leans and it hasn't fallen over yet. It's been leaning for more than eight hundred years. It was built as bell tower. The first stone was laid in 1173, but work was halted in 1187, after the third story was completed, because it was already clear that one side of the foundation was sinking . Causingthe tower to begin to lean
From 1275 to 1284, another architect added three more floors partially correcting the lean. The tower was finally completed at eight stories and a height of 158 feet. In 1350 only a third of the height originally planned. The leaning kept increasing till a few years, whenthe tower was finally stabilized by adding almost a thousand tons of lead to its north side.