Brown Hart Gardens, located off Duke Street, Mayfair, is a 10,000 square feet (929 m2) public garden on top of an electricity substation. The gardens began life as the Duke Street Gardens where a communal garden was laid for what were then working class dwellings in Brown Street and Hart Street. In 1902, the building of the Duke Street Electricity Substation led to the removal of the street level gardens. More information on the Wikipedia page [1].