Italy has played a large role in the history of architecture, discovering important building techniques such as the arch and the dome. Buildings such as the Colosseum, Pantheon and the Leaning Tower of Pisa are examples of such architecture.
"Ahu" are stone platforms on which many moai sit. There are 313 known ahu and 125 of these carry moai. The biggest, Ahu Tongariki is 220 m (720 ft), and had the most (15) and tallest moai.