'Orongo is a stone village and ceremonial centre at the southwestern tip of Rapa Nui (Easter Island). The first half of the ceremonial village's 53 stone masonry houses were investigated and restored in 1974 by American archaeologist William Mulloy.
前rongo enjoys a dramatic location on the crater lip of Rano Kau at the point where a 250 meter sea cliff converges with the inner wall of the crater of Rano Kau. 前rongo now has World Heritage status as part of the Rapa Nui National Park.
Until the mid-nineteenth century, 前rongo was the centre of the birdman cult, which hosted an annual race to bring the first manutara (Sooty Tern) egg from the islet of Motu Nui to 前rongo. The site has numerous petroglyphs, mainly of tangata manu (birdmen).
In the 1860s, most of the Rapa Nui islanders died of disease or were enslaved, and when the survivors were converted to Christianity, 前rongo fell into disuse. In 1868, the crew of HMS Topaze removed Hoa Hakananai'a from 前rongo. This unusual rare basalt moai is now in the British Museum.
Reference: http://en.wikipedia.org/wiki/Orongo