Leaning Tower of Pisa
After the initial astonishment that the Leaning Tower of Pisa does exactly what its name suggests, there is very little else to see or do here—besides watch other tourists set up photos of their fingers pushing, pinching, or lifting the tower up (you may even want to do it yourself). Admission to climb the steep 300 steps to the top of the tower costs €15 (about $20.31 U.S.; check XE.com for current exchange rates), and may cause vertigo.
(Photo: McPig via Flickr. Type of CC Attribution. http://www.flickr.com/photos/mcpig/)