Big, Bigger, Biggest

Season 3 Episode 3: Metro

Over 4 million people use the London Underground every day. Find out how four key inventions in a series of landmark metro systems helped it become the biggest subway in the Western world.

Genre:

Documentary

Seasons:

3

Episodes:

20

Cast:

Quality:

HD

Duration:

50 min

First Air:

2008

Rating:

6.8