Colossal

Where: Rome, Italy
When: June 2011

Some facts you may or may not know about the Colosseum in Rome: It had 80 arches on every level; more than 5.2 million people visited the place in 2012 -- more than the Pompei excavations, the Uffizi gallery and Sant'Angelo Castle combined; much of the original material used to build the ampitheater exists in other buildings throughout Rome; and the building was used for about 450 years, or roughly the same amount of time it took to build the new Wembley.