Brno Underground, Medieval tunnels and crypts in Brno, Czech Republic.

Brno Underground is a network of tunnels and chambers carved deep into bedrock beneath the central streets of the city. The system connects multiple sections, ranging from large vaulted rooms to narrow passageways.

The network originated in the Middle Ages when residents created storage spaces for food, wine, and goods beneath their houses. Later, the spaces were repurposed and adapted over the centuries for different uses.

The ossuary under St. James's Church was discovered in 2001 and opened in 2012. A three-chamber crypt was prepared beneath the church floor to store bones from the churchyard, and in the 18th century the remains began to be stacked in regular rows.

Tours start at separate addresses: the Labyrinth entrance is house No. 21 on Zelný trh, the mint master's cellar and New Town Hall cellars are on Dominikánské náměstí, and the ossuary lies under St. James Church on Jakubské náměstí. Each section is visited separately, so check which entrance your ticket names before setting out.

The ossuary under St. James's Church was discovered in 2001 and opened in 2012. A three-chambered crypt was prepared beneath the church floor to store bones from the churchyard; in the 18th century they were stacked in regular piles, and in 1741 the ossuary was extended under the former cemetery and connected to the church crypt.