Operating Hours : 0800 - 1530 (Saturday - Thursday)
0800 - 1400 (Friday)
Closed every Monday and public holidays
Admission Fee : IDR 5000 per adult
Parking Fee : IDR 3000
The museum is situated across the field from Keraton of Yogyakarta. It was almost empty when I visited. Expect to spend less than 2 hours here as you should get to view everything with no interruption from others.
You can choose to hire a guide but you should still be able to understand if you go around on your own. I thought the labels were pretty good but go ahead if you want an in-house guide.