Hidden Beneath the Cities

S1 E9 | Subterranean Seoul and Railway Revealed

0h 44m|TVPG|Documentary|NGC|National Geographic|2026
Discovering a massive underground chamber hiding under the Seoul subway; visiting a medieval knight's limestone tomb in Poland; examining Roman ruins beneath a church in England; pondering the identity of a 10-million-year-old fossil in Los Angeles.
Hidden Beneath the Cities