The Upper Seletar Reservoir is one of the four reservoirs that bound the nature reserves. The other reservoirs that bound the nature reserves are the MacRitchie Reservoir, the Lower Peirce Reservoir, and the Upper Peirce Reservoir. Built in 1920 and officially opened by Her Royal Highness, Princess Alexandra, The Honorable Lady Ogilvy on 10 August 1969. In 1992, it was renamed as the Upper Seletar Reservoir and became a marked historic site in 1999. With 15 hectares of natural vegetation, the park is teeming with flora and fauna, making it a favorite spot for nature lovers.