
© Scuba Dive Jacek Frydrych, 45-332 OPOLE
Slovak opal mines – Gateway tunnel JOZEF
The opal mine has 17 levels, 4 of which are flooded, and the deepest point is almost 70 m below the water level. The flooded tunnels stretch for almost 5 km. The water temperature is 4-5 ° C, visibility is about 20 meters, but it deteriorates quickly due to soft sediments on the walls and ceiling.