Boris Johnson was one of the passengers on a 19th century tube train which travelled through London today to mark the 150th anniversary of the underground.
He said there was something "very romantic" about imagining all those Victorians in the carriages.
A steam train which carried passengers in the 19th Century has returned to mark 150 years since the first tube journey.
A look back at some of the stops on London Underground's 150 year journey.
All day we've been adding fascinating facts about the Tube, which turns 150 years old this week. Now find out how much you know.