The overhaul of the Bay Bridge is one of the biggest construction projects in the country right now. After almost a decade California is nearing the crucial end of what has become its most expensive public works project ever the $6 billion dollar rebuilding and earthquake-proofing of the Bay Bridge. This massive overhaul involves building an entirely new approach into San Francisco retrofitting the 4.5-mile double suspension bridge with more than 17 million pounds of structural steel and completely replacing the 2.2-mile cantilever bridge with a self-anchored suspension bridge a skyway and new touchdown into Oakland. With the world getting better and better every second the quest for perfection is at its limit and beyond. The quest of perfection is getting insatiable and there are some insanely big and ambitious projects underway. Here are the mega projects which promise to further enhance the world we currently live in. Engineering projects around the globe keep getting bigger and more ambitious. there are structures being designed and built that will dwarf anything that has come before. Plans are on the drawing board for projects so huge – not only in scale but in their implications for society – they’re almost beyond imagination. This documentary that eyes the largest construction projects ever imagined – 'Extreme Engineering'.