4 0   km ▁into ▁K wa Z ulu - N atal . ▁ ▁A ▁great ▁number ▁of ▁rivers ▁arise ▁in ▁the ▁D rak ens berg . ▁These ▁have ▁cut ▁fairly ▁deep ▁valle ys , ▁and ▁occasionally ▁g org es , ▁into ▁the ▁K wa Z ulu - N atal ▁landscape ▁giving ▁the ▁province ▁a ▁very ▁h illy ▁appearance . ▁The ▁Valley ▁of ▁a ▁Th ous and ▁Hills , ▁between ▁Dur ban ▁and ▁Piet erm ar itz burg , ▁is ▁particularly ▁spect ac ular . ▁The ▁largest ▁of ▁the ▁rivers ▁is ▁the ▁T ug ela , ▁portion ▁of ▁whose ▁waters ▁are ▁p ump ed ▁over ▁the ▁Esc arp ment ▁on ▁to ▁the ▁High vel d ▁to ▁supp lement ▁ ▁the ▁water ▁supply ▁to ▁the ▁large ▁industrial ▁cities ▁of ▁G aut eng . ▁ ▁The ▁province ▁contains ▁rich ▁areas ▁of ▁b iod iversity ▁of ▁a ▁range ▁of ▁fl ora ▁and ▁fa una . ▁The ▁i Sim ang alis o ▁W et land ▁Park ▁and ▁the ▁u K h ahl amba ▁D rak ens berg ▁Park ▁have ▁been ▁declared ▁UN ES CO ▁World ▁Heritage ▁S ites . ▁The ▁i Sim ang alis o ▁W et land ▁Park , ▁along ▁with ▁u K h ahl amba ▁D rak ens berg ▁Park ▁and ▁N d um o , ▁are ▁wet lands ▁of ▁international ▁importance ▁for ▁mig rat ory ▁species , ▁and ▁are ▁designated ▁as ▁RA MS AR ▁sites . ▁South ▁Africa ▁signed ▁the ▁ 1 9 7 1 ▁RA MS AR ▁Convention ▁to ▁try ▁to ▁con serve