Chris Tarrant: Extreme Railways - Season 3 Episode 4 -

Documentary series in which Chris Tarrant explores the world's most extreme railway lines. Chris travels on the historically Soviet Trans-Caucasus Railway, beginning in the Azerbaijani city of Baku before exploring the Geogian capital Tbilisi's vintage metro system, then a mountain rail bridge designed by Eiffel, and finally a tunnel reputed to be held together with egg yolk.