The world famous Pisa Tower was built over a period of about 177 years. Soon after the construction started in 1173 the tower began to sink due to a poorly laid foundation and was left alone for almost a century. When the construction resumed the engineers built higher floors with one side taller than the other to compensate for the tilt and the tower was finally finished in the 2nd half of the 14th century. Since 2001, the famous tower in Pisa is again open to those wishing to climb it’s 296 steps