I did Southwest Splendors last year (not an Adults Only trip) but it ended up that the youngest person on the trip was the 21 year old daughter of one of the couples on the tour. There was a couple in their 30's, and the rest of us ranged from 30's to probably 70's, everywhere in between. The trips are great whether you have kids or not. I signed up specifically for an Adults Only tour this year (Alaska) because I felt I really liked the dynamics without kids (not that I don't like kids... but I know I'd be stressed out if there were misbehaving kids I had no authority over). So it's really up to you. I know I've read lots of trip reports of people, both singly & in couples, who have traveled without kids and totally enjoyed it. It's pot luck! All you really need is to enjoy traveling and being taken care of!
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