<P> The vegetation of the Upper and Lower Karoo is similar, so that few people make a distinction between the two . </P> <P> The main highway (the N1) and railway line from Cape Town to the north enter the "Lower Karoo" from the Hex River Valley just before Touws River and follow a course about 50 km south of the Great Escarpment up to Beaufort West . Thereafter they gradually ascend the Great Escarpment along a broad valley to Three Sisters on the Central Plateau and the "Upper Karoo". </P> <P> Turning north from the N1 between Touws River and Beaufort West, at Matjiesfontein the road ascends the Great Escarpment through the "Verlatenkloof Pass" to reach Sutherland, at 1456 m above sea level, which is reputedly the coldest town in South Africa with average minimum temperatures of - 6.1 ° C during winter . Parts of eastern the Mpumalangan Highveld do at times experience lower temperatures than Sutherland, but not as consistently as Sutherland does . Snowfalls are not infrequent during the southern winter months . The South African Astronomical Observatory has an emplacement of telescopes about 20 km east of the town, on a small plateau 1798 m above sea level, and is home to the Southern African Large Telescope (SALT), the largest optical telescope in the Southern Hemisphere . To the north, still on the Plateau, and 75 km north - west of Carnarvon seven radio dishes form part of the Square Kilometer Array which will, 2500 in total, be scattered in other parts of South Africa and Australia, to survey the southern skies at radio frequencies . Our Galaxy, the Milky Way, one of the main targets of this enterprise, is best viewed from the Southern Hemisphere . The Upper Karoo is indeed an ideal site for an astronomical observatory . This is not only because of the clear skies, absence of artificial lights, and high altitude, but it is also tectonically completely inactive, meaning that there are no nearby fault lines or volcanoes, and therefore experiences no earth tremors or earthquakes even at great distances . </P> <P> The Little Karoo is separated from the Great Karoo by the Swartberg Mountain range . Geographically, it is a 290 km long valley, only 40--60 km wide, formed by two parallel Cape Fold Mountain ranges, the Swartberg to the north, and the continuous Langeberg - Outeniqua range to the south . The northern strip of the valley, within 10--20 km from the foot of the Swartberg mountains is most un-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 . </P>

From the north pole south what is the first type of ecosystem encountered