On your initial thought regarding Arizona - just got back from Scottsdale for a stay at the Westin Kierland. It was EXCELLENT. A couple of things regarding the property that may be of interest to your request:

Both the Villas and the Hotel & Spa have separate adult pools, no kids allowed, so you can get some relaxation away from the noise. Mrs. vandalby noted that they did have organized hiking excursions that lasted a couple of hours (I don't believe there was any additional charge). Overall, the pool facilites were phenominal - I mean really excellent. They have a nice, long lazy river in the hotel pool area that I could have floated in for hours.

As a tip - the Villas are now a CAT 5 property and just started accepting points; no need to worry about Platinum recognition as you'll be getting a suite for sure.