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 they are the Tankwa Karoo, the Moordenaarskaroo, the Koup, the Vlakte, and the Camdeboo Plains. The Hantam, Kareeberge, Roggeveld, and uweveldare the better known subregions of the Upper Karoo, though most of it is simply known as the Upper Karoo, especially in the north. The Little Karoo’s boundaries are sharply defined by mountain ranges to the west, north, and south. The road between Uniondale and Willowmore is considered, by convention, to form the approximate arbitrary eastern extremity of the Little Karoo. Its extent is much smaller than that of the Great Karoo. Locally, it is usually called the "Klein Karoo",