The underground caverns (approx. 200 m) lie right in the centre of the town of Zwiesel, behind the town hall. The prevailing view today is that these tunnels originated between the 6th and the 9th century. In 2007, parts of the system of tunnels were restored and opened to the public.
- Capacity / Logistics: The caverns are approached via public, hard surface roads. Parking is possible directly next to the access shaft. Access via a spiral staircase
- Power supply: electricity connection available right in the caverns
- Condition: maintained