There are many arenas with the hyperbolic parabola roof. The one in Athens, one in Finland, the old arena where the Capitals played. There was a thread on the old board that had pictures of many of these arenas around the world.
Make your own hyperbolic parabola:
http://hverrill.net/pages~helena/origami/parabola/
The math behind it:
http://mathworld.wolfram.com/HyperbolicParaboloid.html