Just inside the Mirage, there's a glassed room off to the side, where you can observe a lone white tiger. This white tiger is only a preview of the actual exhibit. If you're looking for a good daytime "family" activity (they stop letting people in at 3:30, it closes at 5), this is a good, fairly cheap one.
To get there, head towards the back doors of the Mirage, and head outside. To your left is the Mirage pool, and to your left is a pathway leading towards the Gardens. At the gate, you pay an entrance fee of $10/person. Through the gates, everyone gathers on a bridge as a tour guide waits for enough people to begin the tour (about 5 minutes).
The tour guide leads you to a platform overlooking the pools that the dolphins swim in and gives you a brief history of each of the dolphins (when they were born, their sleeping habits, their names, etc.). Then, the group heads beneath the pools, for some up close action through the see through pool walls. The dolphins swim very close to the glass and it's as if they know you're there! You also get to see another pool where the younger dolphins live. While under the pool, the group gets to watch a video of one of the dolphins being born. Out of the "tunnel," the tour guide leads you above ground to another pool, where there are even more dolphins!
From there, you head into Siegfried & Roy's Secret Garden. Just past the gift shop, under a greenery-covered archway, everyone gets their "personal tour guide" (a stick with a speaker on it, that allows each person to dial in a code at each animal they are looking at and hear all about that particular animal - some from Roy himself!). From there, you are allowed to roam inside the habitat.
The habitat consists of a large U-shaped sidewalk, surrounded by the different animal's homes (behind a metal fence). Some of the animals in the habitat are changed out on a regular basis. To the left is where the elderly elephant lives with his friend, the rooster. Towards the back is the gorgeous black panther, and in the center of the "U" are back to back "homes" of white tigers and lions. On the right side, there are more tigers and lions and a cougar.
While we were there (at dusk), all the animals were very lively: play-fighting, walking around, drinking water. We were entertained for almost 2 hours. You are pretty close (through the fence) to the animals and there are numerous picture opportunities.
When you are finished there, you can head into the gift shop and buy plush white tigers, postcards, books and calendars about Siegfried & Roy's animals, or a tiger-shaped slinky that makes tiger noises (our personal favorite), among other things.