In the United States, the term mole people is sometimes used to describe homeless people living under large cities in abandoned subway, railroad, flood, sewage tunnels, and heating shafts.

Dark Days is an American documentary film directed, produced, and photographed by the English documentarian Marc Singer that was completed and released in 2000. Shot during the mid-1990s, it follows a group of people who lived in the Freedom Tunnel section of the Amtrak system at the time. DJ Shadow created new music for the documentary and also let Singer use some of his preexisting songs.