Mole people
In the United States, the term mole people (also called tunnel people or tunnel dwellers) is sometimes used to describe homeless people living under large cities in abandoned subway, railroad, flood, sewage tunnels, and heating shafts. == In documentary film and non-fiction == Dark Days, a 2000 documentary feature film by British filmmaker Marc Singer, follows a group of people living in an abandoned section of a regional rail tunnel in New York City, in the area called Freedom Tunnel.