The Zambezi rises with considerable modesty in northwest Zambia from a small spring on the gentle upland of the Southern Equatorial Divide – the watershed that separates the river from north-west-flowing tributaries of the Congo (Figure 15.1). For some 30 km, the Zambezi headwaters flow to the north, towards the Congo, but then the course swings to the south-west, around a low ridge of Karoo sandstone known as Kalene Hill. This direction is maintained for a further 200 km into Angola before the river finally turns south-eastwards to the Indian Ocean. It is with such indecision that southern Africa’s largest river commences its course.