You can walk into the Atlantis and walk around all you want. There are some thing that are only for the hotel guests. You can see a lot of marine live from the aquarium for free. It's not like any other aquarium you've ever seen. If you look at the picture below you'll see some people standing by what looks like a large window with a blue light.
This is some of the things they are seeing...
My pictures don't do the awesome view any justice—I don't know how else to explain it.
They have more to offer for a price, but I never thought is was worth it. You'll have to call the Atlantis Resort for more information about the WALK THROUGH UNDERWATER TUNNELS