Leaning Tower of Pisa

In 1589, Galileo Galilei conducted various experiments on gravity at the Leaning Tower of Pisa. (PROSE: A Matter of Gravity)

Cesare Borgia asked the Doctor what he thought of the Leaning Tower of Pisa, who answered "[that] it looked fine to [him]" (TV: Time Heist)

In 2012, Brian Williams visited it with the Eleventh Doctor. (TV: Dinosaurs on a Spaceship)