Glenbrook Lagoon is a heritage-listed site located in the suburb of Glenbrook in the Blue mountains 10 kilometres west of Penrith and 3.8 km from Nepean river. The lagoon is a natural flat-bottom freshwater lagoon with an average depth of 2.7 metres and a maximum depth of 4.05 metres. The lagoon covers an area of 7 hectares. It relies on waterflow from the surrounding area. The lagoon is also fed by natural springs. Glenbrook Lagoon is one of only three lagoons of this kind in the Hawkesbury area water catchment. Over the past centuries, the lagoon has had several uses. The lagoon and its surrounding area provide an important natural sanctuary for native flora and fauna. Currently the lagoon is used as a nature reserve and tourist attraction. Glenbrook lagoon is of great cultural and historical significance to the people of the Blue Mountains. It is surrounded by a flat walking with quiet street frontages.