Test pilots and engineers embark on the first flight of the largest airplane ever built: the Stratolaunch, a one-of-a-kind aircraft designed to transport rockets, spacecraft and experimental hypersonic planes into the stratosphere.

Engineers in China are constructing the largest and most ambitious water transfer project in human history, defying nature to move vast quantities of water from the south to the dry north in Beijing, all without the use of pumping stations.

Explore three battlefield behemoths that command land, sea and air.

The Falkirk wheel is the first and only rotating boat lift, capable of moving 600 tonnes of boat and water over a 25-metre height difference in just minutes.