The Please Touch Museum in Philadelphia just relocated to an amazing new building (Memorial Hall in Fairmont Park).  We were able to attend the invite-only day prior to the museum's opening last Saturday.

As usual, I had to haul my son out kicking and screaming and wailing.  I'm sure the howls of "I DON'T WANT TO LEAVE*" will echo off the amazing marble atrium for years, but that's just because the museum is so excellent.

I'd say that most of the (exhibits? play areas?) stuff has a bottom age limit of 5 years, and a top age limit of "can fit on the whatever," but my 3 year old was able to play with and enjoy pretty much everything.  I didn't think we were going to see anything but the kid-size excavators, which scoop, move, and dump plastic balls, but in fact it was the water table where he stayed for hours. 

Other attractions include a treehouse; cars and buses to drive, repair, and wash; and various fantastic space machines.  There's a really cool room where kids can build their own gliders, crank them up to the 50-foot ceiling, and let them glide down.  The subterranean level is a busy town, with houses (my son loved mowing the yard, and delighted in finding a (stuffed) pet kitty in one house, stores, a TV studio, a hospital, and a construction area.  Busy town leads to the train station, where birthday party rooms look like Orient Express style rail cars.

It turned out to be educational also:  when we returned home, my son explained to his father how locks work:  "The shark could just swim in the water downhill all by himself, but to go back uphill he had to use the water stairs!"