The Daily Mail has an interesting article on the South Wales cave system.
From what I know about caves, not a lot, they are formed by water. This photo shows a section of the caves that looks suspiciously worked by tools rather than worn down by water.
At one point the caves open up high up in the cliff to look out over the coast.
Something similar can be seen on the north Yorkshire coast where iron workers, following the seam, knocked a huge hole in the cliff face except in their case they were looking across the sea to Denmark.
A rather learned report for cavers about the system touches on anomalies in the directions etc of the tunnels. Some of them are at right angles, some climb and then descend, some are suddenly blocked. The text and language of the article is similar in style to that favoured by trainspotters so for my little brain is rather obtuse.http://www.ubss.org.uk/resources/procee ... 03-325.pdf
The caves are very old, 'The oldest caves of Wales date back to around 1 million years, and the earliest evidence of man are some Neanderthal remains discovered in Pontnewydd Cave, Denbighshire which are dated to around 230,000 years ago. Since then we have had numerous ice ages and our land connection with the continent has disappeared. During the last ice (ending around 10 000 years ago) much of the life in Wales was wiped out or moved to warmer climes (including our ancestors), and had to recolonise Wales as the ice retreated again.'
This quote is taken from this website. http://www.cambriancavingcouncil.org.uk ... index.html
A virtual tour of the caves can be accessed here. http://www.ogof.net/
The Daily Mail article in all its glory is here, http://www.dailymail.co.uk/news/article ... Wales.html
We know that cave systems are formed by water seeping underground, especially in limestone areas. But could they have been altered and modified by early people either as shelters or a mining start up venture?