Based on my observations of the children at the museum, the 4-11 year olds were enjoying the museum. Most the the 12+ children appeared disinterested.

Best deal is go on the parking websites for philadelphia, I think it's SP+, and you can get a discount voucher for their garages. I always park at the JFK house on 19th and JFK it's about a two block walk up 19th to the side entrance to the academy and on the weekends if you pay online it's $12.

There is a surface lot directly behind the Academy of Natural Sciences. The address is: 114 N 19th St, Philadelphia, PA 19103 We have used it several times. It costs a few bucks but is worth it for the convenience. Cheers!

Yes. You could eat it in the cafe.

I just was there for a day visit. I didn't even know the museum had sleep over events. Sorry I couldn't help :(. I think your best bet is to call the museum and ask that question: Phone: (215) 299-1000

At least two hour though I would plan on half a day. It depends on who is with you and the interest and attention span of the participants. Hope that helps!

I was there with a 4 and a 12 year old, and spent about 2.5-3 hours. It was a little long, and the younger child was getting bored. The age gap didn't help, so doing things with one child was sometimes less interesting for the other. I think 2 hours could have been very sufficient. Take a little time to map out a plan, too. We spent a bit of time bouncing back and forth from one area to the other to try and find things, which wasted some time and tired the kiddos a little.

10 minutes, 15 minutes if you walk slowly. If you enlarge the map for site you can see the (30th Street) train station, just across the river. The museum is effectively at 19th street, so including the bridge it is 11 city blocks (not avenue blocks) east.