Actually, I think the National Zoo is pretty terrible. Other than the Panda habitat, at least as of the last time I was there (Spring 01), the majority of the animals were just in cage like structures, not in natural type habitats. The National Zoo really depresses me. I much prefer the Bronx Zoo. They are constantly working to make their animals as comfortable as possible, even if it means the zoo patrons can't see them half the time.