Guggenheim Museum Bilbao

You're standing at the Guggenheim Museum in Bilbao, on the banks of the Nervión river. Look at those shimmering shapes. Curving walls, tilted surfaces, as if the building might topple over or swim away at any moment. It's clad in around thirty-three thousand wafer-thin titanium plates, laid like the scales of a fish. One critic called it a fantastic dream ship. According to architect Frank Gehry, the curves are there to catch the light.