Abandoned sand mines under Prague
It is located beneath Prague and consists of an extensive network of corridors created by sandstone mining since the 19th century. This sandstone was used not only in construction, but also for scrubbing pots and floors. Mining was done by hand, which led to the creation of a labyrinth of corridors, some of which are up to 700–800 meters long.
The underground consists of several parts, the most famous of which are Močálka and Amerika I. Močálka, originally Hampl's sandpit, is known for its winding corridors and damp environment, which was created after a water accident. Amerika I is a smaller part of the system, which has two floors, but due to the number of cave-ins, exploring it is dangerous.
During World War II, the underground served as an air-raid shelter, as evidenced by preserved inscriptions on the walls. During the First Republic, unemployed workers lived here, taking advantage of the cool and dry environment of the corridors. There are also rumors of secret passages leading to Stará Boleslav, which Napoleon allegedly used. According to legend, he even rode in a carriage through the underground passages. Currently, the Prague 9 district is trying to make the underground accessible to the public. The project includes the construction of an entrance building and the creation of a thematic exhibition called "The City Beneath the City." However, it is not yet clear when the underground will be open to the public.