Zandvlei is a shallow estuarine lake located on the Cape Flats in Cape Town, South Africa. Historically a dynamic marsh system that would dry up in summer, it has been significantly altered over centuries. The estuary mouth is now actively managed to allow seawater ingress on spring tides, maintaining a brackish environment. The system is fed by several small rivers, including the Zand River, and features a mix of natural and man-made channels, particularly around the Lakeside area and the Marina da Gama housing estate. Its primary ecological role is as a vital fish nursery ground for the region.