Lake Assal is an aquatic wilderness surrounded by dormant volcanoes and lava fields one days travel via tarmac road west from the capital. You will pass Lac Goubet on the way, a seawater loch known locally as ‘the pit of demons’, then pass a stark, apocalyptic volcanic neck separating the two lakes.
In the far south-west of the country on the border with Ethiopia, Lac Abbé is the dawn gathering place for flamingos. You can only reach it by 4WD, and you’ll need to hire a guide and set aside two days to do it. Weird natural chimneys (or fumaroles) dot the foreshore.