This Scheduled Ancient Monument incorporates a working waterworks and a heritage attraction with steam and diesel engines.
The open door right background is into the boiler house with three Babcock and Wilcox water-tube boilers. The large building closest to the camera with the open door is the 1934 diesel house with preserved diesel pumping engines. The building to the left is the Edwardian pumping station of 1905 and that is still in use for the live plant. The engine house for the preserved steam engine is not visible.
I'm a little confused by the comment on SU4924 : Twyford Waterworks that the pumping station "until 1969 applied lime to soften the water" - as lime would tend to have the opposite effect of hardening the water. Anyone know better or have any more details ?