Wales

• Anglesey
• Amlwch Copper Kingdom

• Blaenau Gwent
• Big Pit

• Caerphilly County Borough
• Winding House

• Carmarthenshire
• Carmel National Nature Reserve
• Carreg Cennen Castle Caves
• Dolaucothi Gold Mine

• Ceredigion
• Llywernog Silver-Lead Mine Museum

• Conwy
• Go Below Underground Adventures
• Great Orme Mines

• Flintshire
• Ffynnon Leinw
• Rhydymwyn Valley Works

• Gwynedd
• Bounce Below
• Corris Mine Explorers
• Electric Mountain Visitor Centre
• King Arthur's Labyrinth
• The Welsh Slate Museum
• Chwarel Hên Llanfair
• Llechwedd Slate Caverns
• Sygun Copper Mine

• Monmouthshire
• Dewstow Gardens and Grottoes

• Pembrokeshire
• Lydstep Caverns
• Wogan Cavern

• Powys
• Bone Cave
• Cathedral Cave
• Dan yr Ogof
• Llewelyn's Cave
• Pant y Llyn
• Porth yr Ogof

• Rhondda Cynon Taf
• Lewis Merthyr Colliery - Rhondda Heritage Park

• Swansea
• Cat Hole Cave
• Cefn Coed Colliery Museum
• Culver Hole
• Paviland Cave
• South Wales Miners' Museum

• Wrexham
• Bersham Colliery
• Minera Lead Mines

• See also
• Search Google for "Wales"
• Wales - Wikipedia
• Mines and Caves of North Wales
• Wales Underground. A site with information about a dozen underground sights in Wales.