An underground thermal lake, discovered below a Turkish bath in Hungary, could be one of the biggest in the world.
"The lake was discovered in an 86-metre long, 15-metre high subterranean cave when explorers delved beneath the baths in Budapest.
The Hungarian capital is built above a labyrinth of caves filled with warm thermal water and many have only partially been explored.
Work has been continuing to build a tunnel to give access to the lake and the Hungarian government says it is considering opening it to the public.
Divers have spent the last few weeks exploring the depths of the lake and the limited lighting available in the cave gives it an eerie feel.
Cave expert Szabolcs Leel-Oessy said: "Since we found the room, we have opened the tunnel with our hands, hammers and electronic drills, so now not only 10 divers can go inside, but practically everybody."
Hungary was part of the Ottoman Empire in the 17th century and has a legacy of Turkish baths which remain extremely popular with local residents as well as millions of tourists who flood the city.
Officials in Hungary are now planning to apply to UNESCO to have the cave system declared as a World Heritage Site.
Mayor Zsolt Lang said: "I will be lobbying ministers and the government, to preserve this whole cave system with its lakes under Buda. I think this is an extraordinary, natural beauty of its kind in the world."
The future of the cave system has even been discussed in the Hungarian courts as ministers seek to give researchers all the time they need to explore the site before public access is discussed."
Font: Sky News