Sayama City Museum is located in Inariyama Park. It is a medium sized museum with a large space for traveling exhibitions. Each year in the summer, Sayama City Museum hosts a child friendly exhibition. This year, for the 30th anniversary of the museum, they chose a dinosaur exhibition.
The "Exploring the dinosaur era" exhibition is from the Food and Agriculture Museum connected to Tokyo University of Agriculture. The exhibition started on June 26th and will run until September 5th. During the period of the exhibition they will have craft workshops for children on the first floor. There is no entry fee to the museum for children, but workshops are charged. They are reasonably priced.