It is always great when zoo exhibits blend into a lush backdrop and the size of this enclosure appears to be excellent. I'm guessing that there is an extremely steep drop down from the electric fence, and hopefully a back-up generator in case of a power outage as the barriers are not as impressive as I would have imagined for large primates. On a side note, if you zoom into the photo then there is some kind of black hose in the grass between the two fences.
On the very limited evidence of this one photo, I'm not sure I'd agree! The artificial rocks stand out like sore thumbs - not quite in the Colchester league, but not far off - while the fence at the front looks a bit homespun. Compared to the gelada exhibit at Zlin, for example, or (budget-wise, possibly an unfair comparison) Zurich or the Bronx, this looks a bit ordinary. (I'd rather an ordinary gelada exhibit than nothing at all, mind you).
I saw this exhibit recently. Its a bit like a smaller 'dry' version of Gorilla Island at the (Bristol) Zoo. The flat areas have been laid with turf, the raised hill behind has weeds/wildflowers growing on it. The barriers are all pretty smart and secure. The rocks look good and don't look too out of place. There is also a covered glass-fronted viewing lookout at the end furthest from their indoor area. The one surprise was the rather ugly indoor building- also it didn't look finished- with scaffolding and stepladders in situ- I wasn't clear if these were for the inmates or for workmen!