Just recently, the Tube marked its 150th anniversary.
The first stretch of the Metropolitan Line was opened on Jan. 9, 1863, with regular service to the public beginning the following day. Newspaper accounts show the first trains were crowded with excited passengers.
The pioneering Metropolitan Line sparked a new wave of underground development which today has grown into a 249-mile (402 km) system carrying 1.2 billion passengers each year.
The aging system is credited with good performance during the recent London Olympics.
(KUSA-TV © 2013 Multimedia Holdings Corporation with NBC Universal)