Botswana has one major tourist attraction that you'll hardly find somewhere else. Most river deltas end in a sea or ocean. The 1600 km long Okavango river ends inland with no sea insight, at the Okavango Delta. The Kalahari desert covers most of Botswana and a wet delta with drinking water attracts a lot of semi-permanent wildlife. A favourite activity is looking for hippos in a dugout canoe...
There are more elephants in Botswana than anywhere else.