This museum used to be a cemetary (!) called Kebon Jahe Kober, which was actively used from 1795 - 1975.
You can see all things related to "the dead"...many cool tombstones and equipments used up to the burial service.
(First Photo - cannonball & signage - is courtesy of Bambang Aroeng Binang)
Please check out his site for more cool pics on Museum Taman Prasasti : http://aroengbinang.blogspot.com/2007/09/museum-taman-prasasti.html