Rano Kau is a 324 m (1,063 ft) tall extinct volcano that forms the southwestern headland of Easter Island. It was formed of basaltic lava flows in the Pleistocene with its youngest rocks dated at between 150,000 and 210,000 years ago.
Rano Kau has a crater lake which is one of the island's only three natural bodies of fresh water. Most of the volcano is on the coast and has been eroded back to form high sea cliffs. 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 principal archaeological site on Rano Kau is the ruined ceremonial village of Orongo.