The Omo also has some beautiful landscapes; Nech Sar National Park frames much of the region with mountains, lakes, and forests, and harbors 70-plus mammal species, as well as prodigious crocodiles and the endemic Nechisar nightjar —the latter arguably the world's rarest bird. A geological depression caused by the continental drift of three tectonic plates, the Danakil Depression is one of Earth's most unusual environments.