The 18th century Temple in the Gunnersbury Park in the London Borough of Hounslow overlooking the boating pond. It has been preserved by the Temple Trust between 1994 and 1998.
Gunnersbury Park is a park in the Brentford ward of the London Borough of Hounslow, in west London. Purchased for the nation from the Rothschild family, it was opened to the public by Neville Chamberlain, then Minister of Health, on 21 May 1926. The park is currently jointly managed by Ealing and Hounslow borough councils. See here