In a bid to improve the quality of drinking water in London, the Metropolis Water Act of 1852 prohibited drinking water being taken from the Thames below Teddington Lock and required water companies to filter their water. The New River Company had already built two reservoirs in Stoke Newington in the 1830s. To comply with this act, they added a pumping station and filter beds adjacent. William Chadwell Mylne, acting as Surveyor for the New River Company built The Castle between 1852 and 1856.
By 1936 the steam engines and boilers were replaced with diesel engines and electric pumps. The building was largely redundant by 1971 and the Metropolitan Water Board (who had taken over the New River Company) applied for permission to tear down the Castle and redevelop the site. With the support of local residents and historical associations, The Castle was given Grade II* listing, though it had no use. The site was under threat of development again in the late 80’s before permission was granted for the redevelopment of the building as a climbing centre in 1994.
The Castle Climbing Centre opened in 1995 and is now one of the leading climbing facilities in Europe. In the years that followed, the site has undergone extensive landscaping with the development of an organic garden. Other major works have included building outdoor boulders, increased climbing capacity indoors, and a number of energy efficiency measures to bring this much-loved Victorian landmark into the 21st century.