An over-crowded South Korean city needs a link to a nearby town.
(03:06)Divers test conditions for power supplies and construction underwater.
(03:02)Discover how engineers overcame some the toughest terrain on the planet to create the remarkable ...
Images from the World's Biggest Tent episode of Megastructures.
Take an eye-popping look at the greatest structures and machines ever created as we focus on some of the world's modern-day super-human miracles of construction.