It's a great place for the teenagers to hang out and adults are not allowed. However, you can go up there and take a peek at it, but don't stay too long, especially if there are teens up there.
Yeah, but if you book a cruise that happens to have no teenagers aboard, they will generally open up that area for adult use. Such was the case on my 30-day Hawaii/South Pacific cruise in 2006. We got to use the Oasis several times.
It's a really neat area ... comfortable chairs, hammocks, etc. But, of course, I understand that normally that is an area reserved for the teens, so I would never intrude. I'm just glad I got the chance to use it on that one cruise.