Volcano Trekking · Arusha RegionOl Doinyo Lengai volcano climbEXPERTRisk: HIGHUSD Guided overnight climb…An active volcano that erupts a genuinely unique lava — natrocarbonatite, the coolest and most fluid lava on Earth, black when it cools rather than the usual red — climbed overnight up steep, loose ash slopes to reach an active crater rim by sunrise.View details