no glass/bars, I had no special access to take these photos just walked along the footpath thats on one side of the enclosure. It is the same 2 adult + 2 young in all photos.
As I understand it the zoo stands built into an old rock quarry and makes use of the exisiting high vertical cut rock sides or further quarries out the enclosures.
See the red panda, giraffe, rhino, leopard images etc. Its not mock rock. The huge vulture walk through was open topped (i'm sure a lot are free flighted) thats how high some of the rock faces are.
Look at Doue July 06 44 to see some of the bear enclosure wall.