Underground Tunnel Labyritnh Ravne
Initial research and local legends suggest that the whole net of underground tunnels exist under the Bosnian Pyramid Valley.
Working hypothesis is that these tunnels connect all pyramids and other sites of importance.
Researched area of one of the tunnel sections show intersections at 90 degrees, man-made ceilings and chambers and ventilation shafts.
Several man-made sandstone monoliths have been found with symbols that might represent first European writings.