I visited this WHS in August 2018 in the late afternoon after a pleasant day in Prambanan. Although the museum structure and area is quite big, its condition is not up to standard and the actual space dedicated to Sangiran No. 17 and other Java Man finds is only restricted to two rooms with a couple of stands and display cases. The smaller museums close to the excavation fields are even worse and such an apparently important WHS for Homo Erectus studies is not given the prominence it might deserve, in favour of national pride and school group outings.

Out of all the prehistoric man sites I visited (haven't visited the one in Beijing yet but not too eager to either), this was definitely the worst and apart from the WHS tick for WH travellers, I wouldn't sacrifice anything from the 2 top-notch WHS of Borobodur and Prambanan to visit. Apart from the few animal fossils and ancestor bones on display out of the thousands kept locked in a storage room, the most interesting features of the museum were the informative video of the locals who found some of the fossils and bones (with subtitles in English) and of course the display case with Sangiran No. 17's skull (photo).