Chełm - underground chalk tunnels
Chelm has several Old Catholic and Orthodox churches. The most noteworthy is the Piast Church. The former Uniate church stands on Cathedral Mount. It is surrounded by a complex of religious buildings that were once the bishops' palace and a monastery. The main attraction in Chelm and a unique tourist route are its underground chalk tunnels that run under the city for more than two kilometres at a depth of about 27 metres. The entire route leads through the old chalk passages hewn out by hand. Sometimes, a ghost known as "Bieluch" appears to visitors walking through the illuminated galleries.