A friend and I went last week, we had a 16 month old and two four year olds. We had such a good time, we both bought memberships (it was $24 for admittance and $65 for a two person membership, and they let us pay for the museum visit to see what we thought and then credited our $24 towards our membership). After 4 hours, we still didn't see all the exhibits, because the kids were having so much fun with all the hands on stuff. And the children's museum area even had a place for my toddler to play. We did not do the planetarium or Imax. The membership gets you free admittance to the planetarium, so we will do that on another visit. It was a very pleasant play date and we are thinking about going back next week.