Jihlava underground

INFORMATION: The total length is 25 km and covers an area of 50 000 m2. The corridors are cut into the rock on several levels. They are located under almost all the buildings in the historic centre of the city. The cellars, located 2-4m below the surface, form the first underground floor, from which it is possible to descend to the second floor, to a depth of 4-6m. Under some buildings, a third floor is also excavated at a depth of 8-12m. The temperature underground varies between 8 and 12°C.

In 1978, the so-called "shining passage" was discovered by amateur cavers. The walls of the passage are covered with a whitish coating that glows greenish after being illuminated. The corridor is located about 11 metres below the surface of the ground, 2.1 metres wide and 2.9 metres high and is the greatest rarity and mystery of the Jihlava underground.

Source:https://www.jihlava.cz/historicke%2Dpodzemi/ms-108142/p1=108142