Karoo Supergroup of the country, and in the Lebombo mountains along the Mozambique border. Once the layer of hard lava was eroded away, the softer Karoo sediments over the rest of the basin eroded even faster. However, the dolerite sills resisted erosion, protecting the softer Beaufort and Ecca shales beneath them. This created numerous and widespread flat topped hills, known as Karoo Koppies ("koppie" being the Afrikaans term for hill), which are iconic of the Karoo, and, by extension, the South African landscape. The dykes, or vertical fissures which brought the lava to the surface stand out today as linear ridges extending
Karoo 10–20 km from the foot of the Swartberg mountains is least karoo-like, in that it is a well-watered area both from the rain and the many streams that cascade down the mountain, or through narrow defiles in the Swartberg from the Great Karoo. The main towns of the region are situated along this northern strip of the Little Karoo: Montagu, Barrydale, Ladismith, Calitzdorp, Oudtshoorn, and De Rust, as well as such well-known mission stations such as Zoar, Amalienstein, and Dysselsdorp. The southern 30– to 50-km-wide strip, north of the Langeberg range, is as arid as the western Lower Karoo, except