The San Diego Zoo does have old bear grottoes like this one for the spectacled bear, but they are still some of the best grottoes I've seen in a major zoo. For example the Pittsburgh Zoo has perhaps 5 feet of dirt and the rest is pure rock in their brutal bear pits.
Now that they have blasted out the concrete floors, added soil, plants and water they are much better. But the canyon is still just a random "stamp collection" of animals. Where San Diego has attempted to do a geographic theme (Tiger River etc.), the results are much better. Bear Canyon and Dog and Cat Canyon both need to be replaced by some new concept.