There used to be two small yards, on opposite sides of the Giraffe House; one between the Giraffe House and the Camel House (now the Tapir House) and one between the Giraffe House and the Horse & Cattle House (now the Okapi House).
It’s difficult to be certain, as they looked almost identical, but I suspect that yard pictured is actually the one on the other side of the Giraffe House to the tapirs; this would tally with there being a kulan the other side of the fence.
These photos of London Zoo represent many firsts for me; first abroad zoo, first bongo, first gaur etc. The living conditions at the time were often highly discutible, especially for ungulates and birds of prey. There was three bongos but only one had access outside, for istance. However, I supposed then as now that the management and species selection of historical zoos, particularly London, was not an easy duty.
I never saw bongo on this level, they were always on rotation on the lower terrace (now the wild dog exhibit).
I never saw wild ass on the Cottons, but I seem to remember a Przewalski's horse in the back enclosure on the camel house side. If the enclosure the bongo is pictured in is the other yard (attached to the cattle house), all I remember ever seeing in this exhibit was anoa, until around 1998 when the yard was added to the okapi enclosure.
It's hard to imagine now, where they put all those animals only a few years ago. I'm sure I remember quite large herds of Scimitar Horned Oryx, Blackbuck and [I think] Axis Deer on the Cotton Terraces, not to mention a selection of wild cattle. All gone now, I believe. How did they fit them all in?