Balmain, Sydney, NSW, Australia
Gladstone Park, Booth Street. The area was originally known as 'The Pigeon Ground' (it was the site of mass pigeon shooting in the early days of the colony), before being purchased by the government in 1882.
In 1890 it was officially opened as 'Gladstone Park' - the first major recreational ground in the area.
This particular structure is the Valve House for the Balmain Reservoir, constructed beneath the park 1914-1915. Made redundant by the commissioning of Petersham Reservoir in 1965, it has remained disused ever since.
From Balmain : Valve House