Kilimanjaro is a giant stratovolcano that began forming about a million years ago, when lava spilled from the Rift Valley zone. Two of its three peaks, Mawenzi and Shira, are extinct while Kibo (the highest peak) is dormant and could erupt again. The last major eruption has been dated to 360,000 years ago, while the most recent activity was recorded just 200 years ago.