The southwest of Rapa Nui
The crater lake Rano Kau, just south of Hanga Roa on the southernmost point of Rapa Nui. The lake at the bottom of the volcano, which is 100 metres above sea level, is covered by floating isles of grass. Legend has it that this lake doesn't have a bottom - that it reaches the very core of Earth. The volcano used to be an essential source of drinking water. The people would climb down the 150-metre high ridge, collect water and climb back up again.