Morphologically, Monte Muambe is ring-shaped feature, composed of Karroo sandstones which rise from peneplain plateau at altitude between 250 m in the south and 300 m in the north. The rim of the caldera forms well-developed circular ridge of altered and indurated Karroo sandstones (gritstones) rising approximately 500 m above the plain of unaltered Karroo sediments. Due to hardness of altered Karroo sediments, after continuous, long-time erosion, Monte Muambe at present is well-developed circular ridge (caldera), basin-shaped, steep-sided and crater-like depression inside. The core of the circular structure is 200 m lower from its periphery.