How Did They Build That?

In Oklahoma, a sacred spiral mound rises on a former oilfield, honouring 39 tribes. London's crumbling Battersea Power Station is reborn with two million new bricks. And in Spain, Frank Gehry crowns a historic winery with floating titanium ribbons.

Milwaukee commissions Calatrava to design a museum with 90-ton wings that take flight. Oslo tears down its national ski jump and rebuilds it for the World Championships. And in LA, a 235 foot tower is wrapped in steel bands to withstand earthquakes.

A typhoon-defying super-tall skyscraper rises over South Korea. In Canada, a record-breaking cable car is suspended above a mountain valley to link two ski resorts. And in San Francisco, a floating 5.4-acre park is built on top of a transit hub.

In Chicago, twin concrete towers push the limits of high-rise design. Engineers conquer the sea to unite Sweden & Denmark. And in Sydney, Norman Foster and team take on the challenge of a new metro station that can't disrupt the busy streets above.

Engineers battle flooding, landslides and unexploded bombs to expand the Panama Canal. In 1960s Seattle, a Space Age icon rises in record time. And in Seoul, Zaha Hadid's landmark pushes construction to the limit with virtually no straight lines.

Norway's gallery bridge twists 90 degrees, houses priceless art and survives a fifty-year flood. Tampa's condemned coaster drops 206 feet beyond vertical. And Brisbane's dockyard gets a $2.5 billion makeover with a Sky Deck no crane could touch.

Zaha Hadid cuts the top off a mountain and builds a museum inside. A Vancouver tower rises clean over a 115-year-old church. And starchitect Santiago Calatrava spans 7 live railway tracks with a column-free glass and steel station.

Lord Foster's five-winged steel towers cool Abu Dhabi's national museum naturally. Robots 3D-print a steel bridge in Amsterdam & a concrete tower in Switzerland. And in Sydney, engineers pump out the harbour to build a fish market beneath the tide.

NASA's 3D-printed Mars habitat rehearses human life on the red planet. Seoul's historic city hall gains a 13-story glass wave. And in Dallas, 68,000 square feet of concrete galleries balance on legs that want to splay open under their weight.

Engineers create impossibly shaped buildings: Albany's Egg, a huge, sculpted theatre space, fit for a Rockefeller; a floating fortress in LA, protecting $2bn in art; and giant New York offices towering over America's busiest commuter rail yard.