We went to visit Shuri-jo Castle yesterday, on the southern end of Okinawa. It was really cool (well, cool to see, but very hot temperature wise).
I think M was a bit disappointed that there weren't any swords, but we saw lots of the history. And the kids collected stamps at various way points, which they turned in at the end to get a page of stickers.
Initial entrance into Shurijo Castle:
Another lion at a different entrance, with cousin B:
A, M, and B getting their stamps, showing that we have been to all the different stations around the castle: