The Czech Republic has a long history of innovative engineering. See how they are meeting the challenges of building Europe"s longest automobile tunnel right underneath the historic city of Prague. Go behind the scenes for exclusive access to the world"s largest castle in downtown Prague. Watch European Truck Racing champion David Vrecký attempt to break the 300 km/h barrier and set a new world speed record. Other stories include a Czech company that makes the best plastic explosives, the largest earth-moving excavator in Europe, and the biggest beer spa in the world.