I have very few photos, but I remember it being one of the most beautiful sites for a wildlife park, as the photos of its remains might suggest.
I saw the park around 1985, back then there weren't so many Eastern colobus in UK zoos and I saw my first group of these at Penscynor. They were in a more ordered, open area of the park with gardens and flowerbeds, near to a large greenhouse. I vaguely remember some kind of walk-through tropical house. I remember capuchins in this area as well. There were no safety barriers round the colobus cage. Some primate enclosures were linked with overhead wire tunnels.
The photos that have surfaced online of the ruins are generally of the sloping wooded hillside along which the 'alpine toboggan run' was routed. There were multi-level viewing primate cages along here (I remember pig-tailed macaques and I *think* woolly monkeys), and lower down was the 'new' chimp island built around 1983 (a tiny, walled concrete island). There were gibbon islands (the guide book at the time pictured 'Cosmo', a concolor gibbon, but I only remember lar gibbons), and a small-clawed otter pool. There were many aviaries for parrot and sofbilled-bird species. The guide book also mentioned sika deer and a free-flying great Indian hornbill, but I don't remember either. I think later the park housed jungle cats, but I'm not aware of their being many other ungulate or carnivore species, it was mainly primates and tropical birds.
That said, I remember guanacos wandering the car park, a lone southern sea lion (which later died, its pool was converted for a meerkat exhibit), and the penguin enclosure, still visible in the link. I'm sure I remember them being lower down the hill, with a small, square, tiled pool which they shared with a white pelican. I remember a trout pond and welsh goats higher up the hill. There may have been free-roaming storks/cranes on some of the lawns also.
I would be interested in any clarifications or elaborations on the above.