More of a ramble than an explore of the Manifold Valley
Ecton Hill is home to dozens of Copper Mines. There are shafts and adits all around the area.
The main one is the Ecton Deep Adit, driven in 1774. The photos below show the engine house, built in 1778 for a Boulton and Watt steam engine.
Although most of the adits are gated and locked with a steel door there are a couple that are open.
I didn't venture much further than a couple of hundred feet in them due to lack of equipment.
Thor's Cave is the highlight of the Manifold Valley, although there are several other caves in the area that a good OS map will show.
Mrs Gibbo (5' 9") kindly poses at Thor's Cave to show the sheer scale.
Links:
http://books.google.co.uk/books?id=h...um=8&ct=result
http://www.kachuzyn.fsnet.co.uk/homepage.htm
http://www.pdmhs.com/pg_ClaytonAdit_001.asp