Like a giant oblong mushroom sprouting up in Tokyo's reclaimed waterfront, the Ariake Sports Center is an unmistakable building. The mushroom look is enhanced by the fact that it's nestled next to a tall smokestack -- the modern-day equivalent of a tree trunk. That cozy relationship is useful because the sports facility's swimming pool is heated with the excess heat from the incinerator.

Not everyone buys the mushroom analogy, and some think of the sports facility as a spaceship. From ground level, that's easy to understand considering the ornamentation on the ends that look like thrusters, a lateral band of windows, and the height of the saucer section that makes it look like it's floating or walking over the landscape.