Once one of the biggest slate quarries in the world but all that remains today is an adventure playground for climbers and really, you are not even oficially allowed to go there at all.
In one of those holes scenes for "Clash of the Titans" was filmed.
Wales (Cymru in the Welsh language) is part of the United Kingdom of Great Britain and Northern Ireland. The major cities are Cardiff, Swansea, Newport and Bangor. The city of St. Davids is the smallest city in the UK with a population around 2000. Wales itself has a population of around 3 million. The Welsh language is spoken by around 20% of the population.