Crossness Engines House, in Bexley: grade I-listed Crossness Engines House is a beautifully maintained waste-water pumping station. It was built by Joseph Bazalgette, who was the engineer of London's Victorian sewerage system, and it contains four of the largest beam engines in the world. The building dates from the late 1800s and was vital in improving the health of Londoners. Prior to 1865 the Thames served in some respects as an open sewer - each drain in London led there and the constant deluge of sewage polluted the water significantly. This in turn was one of the causes of the great cholera epidemics of 1831, 1842 and 1852. All of the buildings in this gallery are participating in Open House London, a free event which sees 700 distinctive London buildings open their doors to the public for one weekend. This year it takes place from September 17-18.
