Sandwich Harbour is a partly landlocked reed-lined lagoon at the mouth of the Kuiseb River, south of Walvis Bay. The lagoon fills with water filtered through the dunefield from Kuiseb which has a purifying effect and reduces salinity.

This remote and beautiful area has become a refuge for coastal and fresh water birds and is a legally protected bird reserve as well as being an important breeding site for many fish species including sharks. Day trips with specialized guides can be arranged from Swakopmund.