<P> A great number of rivers arise in the Drakensberg . These have cut fairly deep valleys, and occasionally gorges, into the KwaZulu - Natal landscape giving the province a very hilly appearance . The Valley of a Thousand Hills, between Durban and Pietermaritzburg, is particularly spectacular . The largest of the rivers is the Tugela, portion of whose waters are pumped over the Escarpment on to the Highveld to supplement the water supply to the large industrial cities of Gauteng . </P> <P> The province contains rich areas of biodiversity of a range of flora and fauna . The iSimangaliso Wetland Park and the uKhahlamba Drakensberg Park have been declared UNESCO World Heritage Sites . The iSimangaliso Wetland Park, along with uKhahlamba Drakensberg Park and Ndumo, are wetlands of international importance for migratory species, and are designated as RAMSAR sites . South Africa signed the 1971 RAMSAR Convention to try to conserve and protect important wetlands because of their importance to habitats and numerous species . </P> <P> The region has a varied yet verdant climate thanks to its diverse, complex topography . Generally, the coast is subtropical with inland regions becoming progressively cooler in winter, but hotter in summer (except on the Escarpment). Durban on the coast has an average annual rainfall of 1010 mm . The average midday temperature during summer (January - March) is 28 ° C, with the minimum temperatures in the early morning averaging 21 ° C. In winter (June--August) the average maximum temperature is 23 ° C, and the minimum is 11 ° C. The summer temperatures in Pietermaritzburg are similar to those in Durban, but it is considerably cooler in winter . The temperature in Ladysmith, further inland, in the Tugela River Valley, reaches 30 ° C in the summer, but may drop below freezing point on winter evenings . The Drakensberg can experience heavy winter snow, with light snow occasionally experienced on the highest peaks in summer . The Zululand coastal region, in the north of the province, has a tropical climate with high humidities, supporting many sugar cane farms . </P> <P> Beaches of KwaZulu - Natal are of world - class quality . The warm coastal climate means that visitors are attracted to them all year round . Some of the visitors, however, come for the annual late - autumn or early - winter "sardine run" along the KwaZulu - Natal coastline, south of Durban . Referred to as "the greatest shoal on earth", the sardine run occurs when millions of sardines migrate from their spawning grounds south of the southern tip of Africa northward along the Eastern Cape coastline toward KwaZulu - Natal . They follow a route close inshore, often resulting in many fish washing up on beaches . The huge shoal of tiny fish can stretch for many kilometres; it is preyed upon by thousands of predators, including game fish, sharks, dolphins and seabirds . Usually the shoals break up and the fish disappear into deeper water around Durban . Scientists have been unable to answer many questions surrounding this exceptional seasonal event . </P>

Why are there more rivers in the east than in the west