Cornwall's engine houses are dramatic reminders of the time when the county was a powerhouse of tin, copper and china clay mining. These two great beam engines were used for pumping water (from a depth of over 550m) and for winding men and ore up and down. The engines were originally powered by high-pressure steam, introduced by the local engineer Richard Trevithick. Today one is rotated by electricity. The site also includes the Industrial Discovery Centre at East Pool, which provides an overview of Cornwall's industrial heritage and incorporates a fascinating audio-visual presentation.