@Arizona Docent: I agree with your thoughts in regards to the lion exhibit, and think that in general the vast majority of the "canyon enclosures" at the zoo are nothing but pits and grottoes. But then again I am one of the more critical members of ZooChat when it comes to discussing below average exhibits.
I just found another photo from Washaw taken last month, showing the overall exhibit. It looks like they have improved it from what I remember. It was just bare concrete, but his photo shows grass and logs. So I guess it's not as bad now as I thought.