My mecca. The Berlin Botanical Gardens have the most wonderful greenhouse structures and lay outs that I have ever seen. The garden isn't too bad either, but I spent so much time exploring the greenhouses that I didn't have time to expand to the outside world...worth the round trip plane ticket just to visit. One of the greenhouses is dedicated to orchids, and another is a HUGE conservatory of tropical plants, animals and three story waterfall included. The cactus greenhouse isn't too much to sneeze about either...