vast slate caverns were hewn by local slate miners. The upper cavern was
used by the Royal Navy during the Second World War as a rum store and is
now used as an auditorium and concert venue with seating for 400.
The cavern shown in this panorama is 60 metres below ground
level and features a subterranean lake with incredibly clear water. The
blue-green colour is caused by the presence of minerals in the rock.