Znojmo Catacombs, Underground passage network in Znojmo, Czech Republic

Znojmo Catacombs are an underground tunnel system beneath the medieval city with multiple levels descending four stories deep. The full network spans approximately 27 kilometers, with about 1600 meters accessible to visitors and containing wells, chambers, and connecting passages.

Construction of these underground passages began between the 14th and 15th centuries, aided by skilled miners from Jihlava. The work expanded over generations as the city enlarged its water supply system and adapted the structures for defense.

The nickname "city of ghosts" comes from the smoke that rose from chimneys of seemingly empty houses while residents hid below. Some cellars also served medieval justice: a two-nave hall under the former town hall was used as a torture chamber.

Guided tours take visitors through about 1600 meters of the system, typically starting from Chicken Market, with the best visiting season during warmer months. The underground maze can be slippery and cool, so sturdy footwear and a jacket are advisable.

The passages contain clever defensive features like hidden trapdoors and angled chutes that directed intruders into deep wells during medieval times. These ingenious traps reveal how residents used their underground spaces for protection when threatened.