London Underground

The London Underground (also known simply as the Underground, or by its nickname the Tube) is a public rapid transit system serving Greater London and some adjacent parts of the counties of Buckinghamshire, Essex and Hertfordshire in the United Kingdom.

London Underground

The London Underground (also known simply as the Underground, or by its nickname the Tube) is a public rapid transit system serving Greater London and some adjacent parts of the counties of Buckinghamshire, Essex and Hertfordshire in the United Kingdom.