Oldonyo Lengai, also known as “Mountain of God” in the Maasai language, is an active volcano located in northern Tanzania, near the Great Rift Valley. It is unique as the only known volcano that erupts natrocarbonatite lava, which is highly fluid and relatively cool compared to typical basaltic lava. This lava cools quickly, forming white, gray, or brownish ash that contrasts with the surrounding dark volcanic terrain. Oldonyo Lengai is sacred to the Maasai people, who believe it to be the dwelling place of their deity, and it remains a popular destination for adventurous climbers and those interested in geological phenomena.