Clouds encircle the lofty rim of Mount Elgon, a huge, long-extinct volcano on the border between Uganda and Kenya, viewed in this enhanced satellite image. The solitary volcano has one of the worlds largest intact calderas, a cauldron-like central depression.
Image courtesy of USGS., under PD
The caldera is about 6.5 km (4 mi) across and formed following an eruption, when the emptied magma chamber collapsed under the weight of volcanic rock above it. For active volcanoes in Kenya, see the Natural hazards-volcanism subfield in the Geography section.