▁of ▁the ▁Orange ▁River ▁which ▁d rain ▁these ▁high lands ▁towards ▁the ▁south - west ▁( i . e . ▁away ▁from ▁the ▁Esc arp ment ). ▁This ▁gives ▁this ▁high ▁region ▁its ▁very ▁rug ged , ▁mountain ous ▁appearance . ▁ ▁Central ▁plate au ▁ ▁The ▁central ▁plate au ▁( ap art ▁from ▁the ▁Les oth o ▁High lands ) ▁forms ▁a ▁largely ▁flat , ▁t ilt ed ▁surface ▁which , ▁as ▁indicated ▁above , ▁is ▁highest ▁in ▁the ▁east , ▁s lop ing ▁g ently ▁down wards ▁to ▁the ▁west ▁( at ▁about ▁ 1 , 0 0 0   m ▁above ▁sea ▁level ). ▁The ▁down ward ▁slope ▁to ▁the ▁south ▁is ▁less ▁pron ounced ▁( the ▁southern ▁and ▁south - western ▁edges ▁of ▁the ▁plate au ▁are ▁at ▁about ▁ 1 6 0 0 ▁to ▁ 1 9 0 0   m ▁above ▁sea ▁level ). ▁The ▁plate au ▁also ▁s lop es ▁down wards , ▁north wards ▁from ▁about ▁the ▁ 2 5 °   3 0 '   S ▁line ▁of ▁latitude , ▁into ▁a ▁ 1 5 0 ‑ mill ion - year - old ▁failed ▁r ift ▁valley ▁which ▁cut s ▁into ▁the ▁central ▁plate au ▁and ▁locally ▁ob liter ates ▁the ▁Great ▁Esc arp ment , ▁forming ▁what ▁is ▁today ▁known ▁as ▁the ▁L imp opo ▁Low vel d ▁at ▁less ▁than ▁ 5 0 0   m ▁above ▁sea ▁level . ▁The ▁rivers ▁which ▁d rain ▁the ▁plate au ▁therefore ▁run ▁west ,