Why does the Leaning Tower of Pisa in Italy lean because of a mistake. It has leaned almost since the day the tower was built. In 1173, the people of Pisa, Italy, wanted to build a bell tower. They wanted tower to be the most beautiful bell tower in all of Italy. The city also needed a bell tower because the church did not have one. However, there was problem. As soon as the first floor of the building was finished, the tower started to lean. Builders tries to make the building straight again as they added more floor, but they couldn't figure out how to make it stop leaning. It look almost 180 years to finish the tower. Since then, the tower has lean by another millimeter every year. Today the Leaning Tower has eight floor and is 54.5 meter tall. By 1990, it was leaning by about 4 meter to one side. It was also slowly dining in to the ground. Many people became worried that it would soon fall apart. In 1998, repair work began on the tower, and by the end of 2001, it had been moved repaired again-in another 200 years.