Nice museum to check out if you're around downtown. It's filled with a lot of information and also interactive stations for everyone.
There are some areas that aren't for kids as it's a bit graphic. For adults, those graphic areas really do give you a feel for how crazy things got during that time. Even without the graphic area, the kids can still learn a great deal of things here. There's three levels of things to do. One of the highlights for me was the courtroom where actual trials were held for the mobsters.
The greeter is also very welcoming and funny. The staff keeps you going if you need some help, but they don't get in your way. Overall it's always a good experience here.
If you're local, make sure to tell them and show them your ID to get a local rate.