Hereford Waterworks Museum.
 

I visited this museum for the first time recently, and was very impressed with what I found. A variety of power sources drove different types of pumps, indeed, apart from animal power I don't think there wasn't any power source not illustrated. But the centre pieces are steam engines, particularly a Worth McKenzie triple expansion. Particularly impressive is that on a steam day practically every exhibit is running. On another thread there is discussion about suitable venues for events; I would suggest that this type of museum would be great (although space might be a problem). The museum is entirely run by volunteers and is highly recommended. Following should be a few pictures to give a flavour of the site.
http://www.steamscenes.org.uk/ttu/00005594.jpg
General view of courtyard area.
http://www.steamscenes.org.uk/ttu/00005595.jpg
Starting a Worth McKenzie duplex steam engine.
http://www.steamscenes.org.uk/ttu/00005592.jpg
1851 Harveys of Hayle beam engine.
http://www.steamscenes.org.uk/ttu/00005593.jpg
Hayward Tyler (Rider patent) hot air engine of 1hp.
http://www.steamscenes.org.uk/ttu/00005590.jpg
My favourite; 97 litre Tangye single cylinder diesel engine.
Barry.