Architect Danny Forster takes you inside some of the most head-scratching builds in the world. Join Danny as he meets the men and women tackling the unique challenges of constructing the tallest buildings, the most effective military tanks, the largest luxury cruise ships, and the most extreme thrill rides. How do you build a 3,113-foot-long wooden roller coaster in winter temperatures of minus 40 degrees? Or get your workers safely to and from a worksite on a skyscraper that's 1,614 feet above street level? Or dig a water tunnel - along the San Adreas Fault and 1,000 feet below the earth's surface - without it collapsing on itself ... or flooding? Our intrepid host answers these puzzles and more. Don't miss the big stories behind these even bigger engineering marvels.