Underground steam engine on overnight test run
London Underground's last surviving steam engine is seen here at Moorgate station on a test run before Sunday's special heritage run.
25 facts to mark 150 years of the Tube
It's 150 years this week since the first Tube journey took place between Paddington and Farringdon on the Metropolitan Railway.
Pictures: Stops along the Tube's 150 year journey
A look back at some of the stops on London Underground's 150 year journey.