So, San Francisco has the California Academy of Sciences, which is one of the 10 largest natural history museums in the world.

In 2005, it was closed for complete renovation - they consolidated the entire thing into one huge building of over 400,000 square feet, and built it to state of the art green standards (not that I've turned hippie, but the engineering behind it is impressive). It re-opened about a month ago, and I finally had a chance to go. Man, is it awesome.




The entire roof is covered with native plants, providing insulation, as well as attracting birds and butterflies.




There's a 4-story indoor rainforest, with trees, plants, birds, frogs, and butterflies, just chilling in there with the visitors. At the bottom level of the rainforest, there's a huge pond filled with fish found in the Amazon. You can look down into it from the top level, or take a glass elevator (through a tube in the tank) to the bottom, for better viewing of the fish.

On top of that, there's also a huge aquarium with a giant recreation of a coral reef, and a California kelp forest.

There's also a swamp exhibit, with snapping turtles and alligators (including a rare albino alligator), a huge, state of the art planetarium, as well as penguins.

There are dozens of smaller exhibits, with snakes, fish, lizards, insects (including a colony of leafcutter ants), and several "classic" exhibits you would expect at a natural history museum: stuffed animals in displays, and dinosaur bones.

In conclusion, if you're ever in SF, this should be the first thing you visit.