World's Greatest Bridges

Cutting-edge tech and the latest science are helping engineers build record-breaking bridges that push construction to brand-new heights, and experts reveal the secrets of how these megastructures are being built. This is a mashup of S02E02, "World's Tallest Bridge" (Millau Viaduct) and S05E09, "Himalayan Mega Train" (Qinghai-Tibet Railway).