How Did They Build That?

A sculptural new transportation hub for New York's World Trade Center is beset by challenges. Amsterdam gains a striking building inspired by a mountain valley. And a new launchpad for space travel prepares for liftoff in the New Mexico desert.

A gravity defying university building in Sydney Australia is clad in 320,000 bricks. Engineers grapple with making an angular arts center tornado proof in Oklahoma. And a plant-filled office building made out of three giant spheres takes shape in Seattle

Engineers grapple with an apartment building, ripped apart by a man-made canyon. The iconic Gateway Arch takes shape in St Louis, Missouri. And an unpromising plot in Copenhagen is transformed by a gleaming new triangular office building.

A dazzling new 1400 foot tapering skyscraper is built right next to New York's Grand Central. A curving wine museum requires ingenious engineering in Bordeaux, France. And possibly the world's most glamorous parking garage takes shape in Miami.

A 1.2 million square foot office building balances precariously on a 39 foot wide base in Chicago. A building named Pterodactyl lands on top of a Los Angeles parking garage. And the world's longest suspension footbridge is constructed in Czechia.

A new Olympic and Paralympic museum tests engineers with its trailblazing accessible design. A dazzling curved glass skyscraper battles gravity in Milan. And a student center built under a noisy railroad deploys inventive acoustic engineering.

Architects and engineers build an eco-friendly convention center on Vancouver's waterfront, a lift bridge in Bordeaux, and a cocoon-shaped skyscraper in Tokyo, each with unique challenges like marine habitats, massive spans, and earthquake resistance.

A sculptural high-rise with rippling balconies breaks the mold in Chicago. Mammoth machines bore 26 miles of tunnels for an underground railroad beneath London's city streets. And Tokyo's tallest tower requires extreme earthquake-proof engineering.

A new performance center with a tent-like glass-and-steel lobby tests engineers in Kansas City. Two twisting apartment towers make heads spin in Ontario. And a Miami museum gains a 4.5 million gallon shark tank, with a 31 foot wide viewing window.

The American Museum of Natural History in NYC gets a mind blowing cave-like extension. An arts center inspired by migrating birds is built on a lake in China. Boston University gains a fossil-free, Jenga-like tower.