From 1999 to 2011, the MGM Grand resort in Las Vegas featured a large lion exhibit as part of the casino hotel's attractions. Constructed for $9M, it was a detailed habitat which allowed the lions a chance to wander and play, while humans could observe them from a surrounding glass wall as well as a glass tunnel running through the display.
It was a spectacular and beautiful exhibit, and dearly lamented when it closed.
If you would like to read more about the reasons for the closure, you will find this interesting.
The lions were relocated and can now be found at the appropriately-named Cathouse (aka The Lion Habitat Ranch).
The below shot -- taken by my wife, not me -- captures two of the lionesses in a sweet moment as they sleep, and the reflection of an admiring onlooker.