In the 2600s, New Yorkers elected a supervillain governor that stole the Leaning Tower and placed it in Monument Beach. This confused Fry, as he didn't know both it and Mount Rushmore were in New New York. The tower was destroyed by the First Omicronian Invasion of Earth in 3000.
By 3001, the tower had been rebuilt in Pisa. During a planet-wide joyride, it was first knocked upright by the Planet Express ship being piloted by Fry and Bender, then knocked over by the Planet Express building, which was attached by the unbreakable diamond tether.