Of particular interest for me were the many exotic fruiting plants and trees. I saw a Calabash tree, several coffee bushes, and a Guatemalan avocado. There were fallen coffee berries everywhere, so I asked a volunteer if I could take some home. She said she didn't know, but she didn't think it would be allowed. I was with the wife and kiddo, so I didn't pursue it any further. I should have though. If I ever get back there, I'll be sure to ask the curator.
Another brilliant thing we saw was how they provide water for the butterflies. I've often heard that you should put mud out for butterflies to get a drink. Butterflies can't drink from birdbaths, and need moist soil to get water. The butterfly center uses red plastic bowls with large scrubby-sponges. Super cheap, and very effective. That very day I went to the grocery store looking for the sponges and bowls, and that afternoon, I set out my new butterfly drinking fountain.