In the vulture/marabou aviary near the viewing window I saw this (potentially fake?) rather large skull. After a bit of research I believe it looks the most like the skull of an eland, but I'm not 100% sure of my determination.
Unmistakable horns of the eland, yes, your ID is 100% sure. If it's a fake skull, then it have a perfection superior to the best imitations in museums - I'm 95% sure that is an authentic skull.
Thanks for confirming my identification, @Kakapo . To me it would seem strange to put a real skull into an actual exhibit rather than use it as a museum specimen, but in a scavenger exhibit you couldn't get much more authentic.
Dierenpark Amersfoort in fact used to have eland in their savanna exhibit until a few years ago so perhaps that is where it might have been sourced.
Unfortunately ZTL seems to be down at the moment and I can't go on there to search for information on this.