Mount Suswa is a striking volcanic marvel in Kenya’s Rift Valley, best known for its rare and geologically significant double crater structure — a feature seen in only a handful of volcanoes worldwide. Unlike typical stratovolcanoes or calderas, Mount Suswa presents a shield-shaped volcanic cone with two nested craters, creating a dramatic, amphitheater-like landscape that fascinates geologists, hikers, and nature lovers alike.
🏔️ Overview of the Double Crater
- Type of Volcano: Shield volcano
- Location: Great Rift Valley, between Nairobi and Narok
- Total Area Covered: Approximately 270 square kilometers
- Outer Crater Diameter: ~10 kilometers
- Inner Crater Diameter: ~5 kilometers
- Elevation: ~2,356 meters above sea level
Mount Suswa’s overall shape is relatively low and broad (shield-type), resulting from fluid basaltic lava flows that spread widely before solidifying — very different from the steep conical shapes of composite volcanoes like Mount Kenya or Mount Longonot.
🌋 How the Double Crater Was Formed
The formation of Suswa’s double crater is the result of multiple stages of volcanic and tectonic activity during the late Pleistocene and Holocene epochs:
1. Initial Shield Volcano Formation
Mount Suswa began forming as a classic shield volcano, composed largely of basaltic lava that oozed gently from central vents along a north-south Rift Valley fissure. These lava flows accumulated to form the broad cone-shaped structure visible today.
2. Outer Caldera Collapse
As magma continued to erupt and empty the underlying magma chamber, the summit region became structurally unstable. The outer crater — about 10 km in diameter — formed when the summit area collapsed due to this magma withdrawal, creating a massive bowl-like depression.
3. Inner Crater Formation
Later, renewed volcanic activity within the collapsed outer caldera led to the development of a secondary, inner crater, measuring about 5 km in diameter. This occurred when magma once again collected beneath the surface and pushed upward, creating a dome-like uplift and subsequent collapse within the existing caldera floor. The process is sometimes referred to as resurgent doming.
This layered formation — outer collapse caldera + inner collapse caldera — is what gives Mount Suswa its rare nested double crater system.
🕳️ What Makes It Unique?
- Rarity: Only a few volcanoes globally exhibit a double crater. Suswa’s is one of the most accessible and visible examples.
- Circular Forest Inside: The inner crater hosts a ring of dry forest, creating a bizarre and beautiful ecosystem that’s visible from the rim.
- Lava Tubes and Caves: Radiating from the lower flanks and base of the volcano are dozens of lava tubes, some several hundred meters long, formed by flowing lava that cooled and hardened at the surface while molten lava continued flowing inside.
- Maasai Ritual Sites: The caves and crater floors are used by local Maasai communities for initiation rituals, livestock grazing, and temporary homesteads.
🔍 Scientific Importance
- Textbook Example of Calderas: Mount Suswa is often used in geology education to demonstrate complex caldera processes.
- Volcanic Rift Evolution: The mountain lies on an active tectonic rift and offers insight into rift valley development and magmatic systems.
- Sediment Studies: Ash and lava deposits within and around the crater are useful for studying environmental changes and volcanic history in the Rift Valley.
🧭 Hiking the Double Crater
Visitors can hike along the outer rim, which offers stunning views into both craters and across the Rift Valley. The inner crater’s rim can also be reached with the help of local guides. Some popular features along the hike include:
- Viewpoints along the eastern and southern edges (ideal for sunrise/sunset).
- Forest in the inner crater, which can be accessed via descending trails.
- Cave trails on the southern and western flanks.
- Maasai homesteads, where you can interact with locals and learn about their relationship with the land.
🛑 Safety and Travel Tips
- A 4×4 vehicle is necessary to reach the mountain.
- Always go with a local guide, especially when exploring caves or descending into the craters.
- Bring ample water, sun protection, and camping gear if staying overnight.
- The inner crater forest is home to wildlife including baboons and snakes — be cautious.
- Mobile signal is poor, so inform someone of your route and expected return.
📸 Photography Tips
- Use a wide-angle lens to capture the double-crater effect from the rim.
- Sunrise and sunset create dramatic shadows and lighting across the caldera.
- Drone photography (check with locals and authorities) reveals the full geometry of the twin craters.
💡 Fun Fact
The forest inside the inner crater is sometimes called the “Crater Forest” — a ring of greenery surrounded by desolate lava fields and cliffs, creating a truly surreal, Jurassic-like atmosphere.
🔚 Final Thoughts
The Double Crater of Mount Suswa is one of the most visually and geologically fascinating volcanic formations in Africa. It combines striking natural beauty with deep cultural roots and scientific intrigue. Whether you’re a hiker, geologist, photographer, or adventurer, this unique volcano offers one of Kenya’s most memorable and underexplored landscapes.