The tower of Pisa is most famously known for it’s distinctive lean (and the horrible pictures that are often taken with hundreds of tourists). The reason behind the tilt is the ground was not strong enough to hold up the tower completely straight. The tower when measured on one side would be 183 feet, and the other (due to the lean) is 185 feet! One of the most famous events that have happened regarding the tower is (reportedly) Galileo Galilei dropping two cannonballs of varying mass at the same time from the tower to demonstrate the speed of falling is not dependent on the mass of the object. More recently, teams of engineers have been working on stabilizing the tower, because without it, it was structurally unsafe. The Leaning Tower of Pisa leans at an angle of 3.99 Degrees, but before the re-stabilization work, it leaned at an angle of 5.5 Degrees. If the tower was perfectly straight, the top of the tower would be 12 feet and 10 inches higher than what it stands at currently. Interestingly enough, the Leaning Tower of Pisa, is not the only famous leaning structure, but it most definitely the most well known!