Besides the seeing the coins being first hand, there are interesting artifacts on display before the escalator takes you up and look down from the catwalk, the different sections of how coins are made. It is a very long walk from one end to the other. Nearing the end, you can interact using a machine to try your skills and questions on podiums to answer as you go through.
Very well stocked souvenir shop, workers are very pleasant. Please restrain though from taking pictures as they request and is posted for obvious reasons.
A must visit.