There was a similar exhibit that mirrored this one, behind this current lion exhibit, with the old gorilla 'house' in between. It held a variety of tigers over the years, with a single White Bengal & a couple of Siberian tigers before it was demolished for part of the African Forest expansion around 2007. I believe all those tigers passed away before it was demolished. It was built around the same time (maybe a year or two later) as this one and had a similar large swimming moat (although I am not sure it was as wide as this one). The exhibit also had an elevated observation deck on the back rock accessible via stairs on both sides. Interesting that this lion exhibit had underground viewing, and the Siberian tiger exhibit had elevated viewing. I'm sure these were built as generic large cat exhibits and both had moats.
I'm sure the land area is bigger than shown here, and I trust the word of others who say it is one of the zoos best exhibits, but imagine how much better it would be if they had access to the huge moat!
I know lions don't like water, but I know they can swim. I've always wondered how quickly things might change in zoos if one day one of these lions just thought about swimming over the moat and walking out!