Chełm, Italy
The Chełm Chalk Tunnels (in Polish Chełmskie podziemia kredowe) are a system of tunnels dug into the chalk under the city of Chełm in eastern Poland. The tunnelling began in the Middle Ages for chalk mining and was discontinued in the 19th century. The tunnels also served Chełm's inhabitants as shel
ters during raids, wars and pillage. The system is now open solely for tourists. In total, the network of tunnels stretches for around 15 kilometres (9 miles).
Listen to the audio guide for Chełm Chalk Tunnels Free on WIP — starts by itself when you arrive, even with the screen off