Long ago, the volcano that made this crater stopped erupting. Over thousands of years, rainwater and seawater seeped in and slowly filled the crater up, creating this calm and shimmering lake. Because some of the water came from the sea through underground cracks in the rock, the water has a gentle saltiness to it.
The lake sits in a bowl of dark volcanic rock, and trees and plants grow right to the water's edge. It is very quiet there — you can hear birds calling and the rustle of leaves. The water reflects the sky so perfectly that on calm days it can be hard to tell where the water ends and the sky begins.
Local children love visiting Lac Salé. It is a reminder that the ground under Comoros is full of volcanic history — even lakes can be born from volcanoes. Scientists say the lake is a window into the island's geological past and still study the water to learn more about how the volcano behaved long ago.