Mega Builders - Season 6

Return to the 57-kilometer long high-speed rail tunnel in Switzerland's Gotthard Mountain range to see what it will take to finish the project by 2017.

Returning to Tenerife to check on the world's best water park which now seems destined to remain dry after numerous problems.

Crews race against the clock to finish an important venue and signature landmark for the 2012 London Olympics.

Mega Builders return to Istanbul to update the Marmaray rapid-transit project, which continues to have delays.

Six years after piles were pounded into the muddy bottom of San Francisco Bay the new Bay Bridge is about to be topped off.

Inside a famous Swedish hotel which is constructed from 10,000 tonnes of ice and 30,000 tonnes of snow, and boasts a frozen bar and cinema screen.