In the north-west of Botswana lie the swamps of the Okavango delta. A vast area of wetlands, varying seasonally from 6000km² to 10 000km², it supports a great variety of fauna and flora in a unique environment embedded within the semi-arid sandy tracks of the Kalahari. In addition to the wetlands is the delta of the Okavango, around 25 000km² in area.