Open air museum in arnhem

Here's the official website for the Openlucht Museum. It should have all the info you need.

There is also a very small museum at the city end of Arnhem's "bridge too far", the famous defeat in WWII. The current bridge is plain and modern. But the museum in the former headquarters of the British airborne is well worth several hours if you are interested in that war's history. It has an especially interesting section recounting how the civilian residents survived the defeat and waited for liberation.

https://en.wikipedia.org/wiki/Battle_of_Arnhem#External_links

https://www.airbornemuseum.nl/en/home