Poseidon Undersea Resort is the world's first seafloor resort. The luxury resort is accessible by elevator, and you sleep 40 feet below surface. They'll even teach you to pilot one of their 3 passenger submaries and "explore the abyss."
So the decor is a bit disappointing compared to what it could be, but there's a lot of potential. Too bad it isn't steampunk.
Thanks to Mr. Jon McDougal for pointing this out.
