Tuko_Pomoja
I'm biased because I attended the school many years ago, but it does have a lot of history and the school is a very unusual one. If you're in town this is the number one must, even above the gaol and Dunera.
SuperDuperCoach
This museum is in the front part of the high school, just near the principal's office. When you enter you go to the school office and get a visitor badge, and they show you aroudn the room with the exhibits then leave you to look around. The exhibits chronicle experiences of locals that enlisted or otherwise served in WW1, WW2, Korea and Vietnam. Many personal artefacts and books of photos from their experiences in Egypt, Turkey etc. Some sad stories. Not very big but really worth seeing. The first place I'd recommend you go when you visit Hay. make sure you time your visit, it is only open when school is on. Definitely suitable for kids 8 yrs + because you can talk to them about the significance of what is on display.