under the Old Town, sometimes also called Stadt unter der Stadt (City beneath the city). Spurred by the city's uneasy past and the soft yet sustainable soil, Oppenheim's medieval inhabitants dug at least 40 km worth of tunnels and rooms beneath the 'visible' city. Among other things, the St Catherine's Church's stained glass windows survived here not only several medieval wars but also WWII bombings. A part of the tunnels have been made accessible to the public. Guided tours (in several languages) are offered by the town’s tourism and festival play bureau. The underground rooms also sometimes host theatre performances and other events.