Lerai

Lerai is the Maasai name for the yellow-barked acacia. A forest of them grows on the floor of the Ngorongoro Crater, against the southern wall.

Schematic cross-section, not to scale. The forest sits against the southern wall, where the ascent road begins.

The forest

The trees are Vachellia xanthophloea, the fever tree, sharing the ground with Rauvolfia caffra. Their smooth bark is a powdery greenish yellow. They grow here because the water table sits high against the crater wall.

Generations of elephants have stripped the bark, leaving trunks that look weathered and half-skeletal. Black rhino shelter in the shade, along with bushbuck, eland and waterbuck.

The caldera

A volcano once standing near the scale of Kilimanjaro collapsed inward about 2.5 million years ago. What remains is roughly 20 km across, 260 km², and about 610 m deep — the largest unbroken caldera in the world.

Walled in on every side, the floor carries some 25,000 animals year-round. The name is said to come from ngoro ngoro, the Maasai word for the sound of cattle bells.

SenetoDescends the western wall. The way in.
LeraiClimbs the southern wall from beyond Lake Magadi, starting at the forest it is named for. The way out.
LemalaOn the eastern side; travelled in both directions.

Three unpaved tracks are the only routes between the crater floor and the rim.