Great Britain is very rich in interesting geology, many famous geologists of the last 300 years were from Britain. Many geological periods have their name from the British towns and areas were they were first described, see the Geologic Time Scale for a list of them.
Mining, industrial revolution and the discovery of caves goes hand in hand. Many of the over thirty show caves in Britain have a mining background, were found during mining activities or used as a natural access to the ores.. And the number of mines is outrageous, which means a lot of work for me still to do.
The geology tells us much about the existence of mines and caves. Caves are typically karst caves, which are only found in soluble rocks like limestone, dolomite and gypsum. They can be found in the areas with sedimentary rocks in the central, southern and western parts of Britain. Some small patches of limestones in Wales and Scotland contain caves too.
Recent volcanism with lava tubes can not be found. But the British Isles have a long and often rough coastline with numerous arches, natural bridges and huge sea caves.
Mines are typically found in the old orogenies of Scotland, Wales and Cornwall with various crystalline and metamorphic rocks and many granite intrusions. The ores are rich and various. Coal layers are found in deep sedimentary rocks of the Carboniferous Era, in the middle of England.
Britain has a long history and so many artificial caves and caverns exist. Cellars and cave houses are very common. But until now there is no cave castle listed. Rather common are shell grottoes from the victorian age. The most recent caverns are bunkers and air raid shelters of any kind. Many nuclear bunkers were opened to the public after they were abandoned at the end of the cold war.