Zandvlei Estuary Nature Reserve (also spelt "Sandvlei") is a 300-hectare (740-acre) nature reserve and recreational area located in Cape Town, South Africa. Entering the ocean in the suburb of Muizenberg, Zandvlei is the only functioning estuary on Cape Town’s False Bay coast, open to the Atlantic Ocean throughout winter and in summer the mouth is manually closed by a sand bar to contain the water, and is opened monthly for a few days at full moon to maintain salinity levels and then closed again. It is also one of the most important estuaries for recruitment of fish such as garrick, steenbras and two species of stumpnose.