If you get fed up with Wheal Coates, there are other cliff-side engine houses. Trewavas Head mine and Rinsey are close together (near Prussia Cove) and of course there are Wheal Owles, Wheal Edward and the two Crowns houses on the cliffs at Pendeen, nr. St Just. If you find yourself in that area, it's worth making a trip to Pendeen lighthouse after dark (i.e. when the pub has chucked out!). Walk down the short path and you can stand almost under the light. Four beams sweep the horizon and it's especially impressive if it's foggy (i.e. quite often!) I shot some slides of it at night last summer, but plan to return with b/w. If you'd like OS references for the mines I mention, let me know.