and
Poike Rano Kau has a
crater lake which is one of the island's only three natural bodies of fresh water. The lake is located approximately above sea level, but is more than below the highest of the crater's ridges. The volcanic cone is largely surrounded by water, and much of it has been eroded back to form high sea cliffs which at one point (
te kari kari) have started to bite into the crater wall. The inside walls of the crater are sloped at an angle of between 65° (steepest, near the crest) and 45° (gentlest, at the lake shore). From the ruins of the ceremonial village of
Orongo the cliff face drops to the southwest at an angle of 50° to the sea shore some below. On its northern side, the volcano slopes down to
Mataveri International Airport. Rano Kau is in the
World Heritage Site of
Rapa Nui National Park and gives its name to one of the seven sections of the park. The principal archaeological site on Rano Kau is the ruined ceremonial village of
Orongo which is located at the point where the sea cliff and inner crater wall converge. One
ahu with several
moai was recorded on the cliffs at Rano Kau in the 1880s, but had fallen to the beach by the time of the
Routledge expedition in 1914. As well as
basalt, it contains several other igneous rocks including
obsidian (for which it was one of the major sources for the island's stoneworkers) and
pumice. The crater is almost a mile across and has its own micro climate. Sheltered from the winds that wet most of the rest of the island, figs and vines flourish at Rano Kau. The inner slope was the site of the last
toromiro tree in the wild until the specimen was chopped down for firewood in 1960. at far right == Geothermal activity ==