While staying at the Aria for a conference I took an afternoon out the visit their spa. Booking was simple - you can just call from your room. Upon arrival I was given a tour of the spa - they have a beautiful relaxation room and a terrace also.
I forget who my attendants were but they were very helpful and not over bearing.
Massage was great and the seaweed detox wrap was so refreshing.
The dry oil they use is great for your skin too.