Probably at least 2 hours. Depending on the interest level and attention span of your group it could definitely be more.
I've been there 4 times and I think at least 3 hrs. Love that place! One of the best and most interesting attractions in KC!!
We were there 3 hours really took our time but enjoyed it all!
It took us about 3&1/2 hours we looked at everything and read everything it was fun & entering
We were there for 2 hiurs. That felt like enough time to do everything but some people in my group said they could have stayed longer.
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