What does Marian Rock hide?

Looking from the Most dr. Edvard Beneš on Mariánská skála, two massive concrete portals of entrances to the rock can be seen above the tracks. In 1939, two tunnels began to be dug here, which were supposed to divert traffic from the center of Ústí through the rock to Krásné Březno during floods. The tunnel was to be 620 meters long, 4,2 m high, 6 m wide and there were to be 8 escape and ventilation tunnels. In September 1939, after the outbreak of World War II world…