As long as the entrances arent beyond public safety to walk around, yes you can see it even if its raining. You'll just get a little wet going to and from the building and entrance to cavern.
Sure can!
Yes you can.
Yes. The guide stated during the tour that there are several levels in the cave. Lower levels fill with water first, and as other comments have mentioned, it takes A LOT of water to rise to the tour levels.
Yes Just bring a lot of bug repellent before you get inside
Yes ,sunshine/rain doesn't affect the tour as its located underground
Yes. Takes a lot of water for them to close.
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