Wookey Hole Caves are opening hidden caverns and tunnels to the public after a £3 million expansion.
Teams who have been working beneath the Mendips have used three tonnes of explosives to blast through the rocks and uncover unseen chambers.
Watch the video below shot by Gavin Newman:
The detonations have also revealed a subterranean lake and a rock formation which experts are struggling to identify.
Wookey Hole have described the expansion as "blasting into the unknown".
The expansion will involve putting in place a new 70 meter tunnel will allow them to explore further into the new cavern.
But it's already been 2 years in the planning and will take around a month to complete before it can be opened to the public.