Divers in Budapest, Hungary has spent the last few weeks exploring the depth of what may be one of the biggest underground lakes in the world. The huge subterranean thermal lake was discovered in early 2008 and in a cave complex below a Turkish bath. A tunnel has been built to give greater access to the lake and the Hungarian government is reportedly considering opening the area to the public.
　　It is special because it is active, in the Budapest under the sea, a lot of caves. Seven big caves and three dozen smaller one(s). Together is 40 kilometers long. Sometimes it's very beautiful precipitations: gypsum, aragonite, calcite, baryte crystals. But all the other cave(s) are inactive and dry.

　　Budapest has built above the maze of the largely unexplored caves, filled with hot thermal water. The heat from that water helps heat the Turkish baths. The government plans to allow the researchers full access to the site prior to making any major decisions about public access and officials are planning to apply to have the cave system declared as a UNESCO World Heritage Site.