The famous Leaning Tower of Pisa has been tilting for over 800 years, and recent improvements should allow it to continue tilting for another 300 more. On August 9, 1173 On August 9, 1173, construction began on this well known Italian bell tower. Almost immediately Almost immediately, it began leaning because it was being erected on the soft silt of a buried riverbed. Between 1178 and 1360 Between 1178 and 1360, work stopped and started two more times as workers tried to continue the project and figure out how to compensate for the tilt. Over the next six centuries Over the next six centuries, the tower’s lean continued to increase, although tourists were still allowed to visit. Then, in 1990 Then, in 1990, Italy’s prime minister feared the tower would collapse and closed it to the public. From 1999 to 2001 From 1999 to 2001, engineers excavated soil from beneath the tower. Now Now, the tower still leans out about 15 feet beyond its base, but it should remain stable for several more centuries.