The Tube London is vastly inter-connected, quite unlike anywhere else in the world, with an expansive, sprawling underground system which, though technically called The London Underground, is locally known as “the tube”.

The slang name for the London Underground is “the Tube.”

This nickname comes from the tube-like, deep-level tunnels that characterize much of the network. It’s widely used by both locals and visitors — you’ll see it on official signage, maps, and in everyday conversation (e.g., “Take the Tube to get there”).

Other less common or more informal terms include:
- “The Underground” (standard term, not really slang)
- “The Metro” (rarely used by Londoners, more common in other cities like Newcastle or abroad)