It's mixed, although part of the outdoor circuit is inside of a bus. I would definitely take an umbrella and/or rain gear with me, if I happen to go there in a rainy day, because it's a big place to visit, and the attractions are far away from each other.
I went in a rainy day. It's kind of messy but you still enjoy it.
You can certainly check it out in bad weather too. There are many shows and activities that are indoor. The rock garden is outdoor.
Most exhibits are indoor. The Atlantis shuttle is definitely a must see (indoor).
Many indoor and outdoor exhibits.
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