In the Caribbean is a new island resort called Sunset Hotel Resort, often contracted to Shotel Resort by their advertising. It's a place that's said to utterly rejuvenate one's body and brighten their mind, to the point that they feel young again. Curiously it isn't particularly expensive, and even more curiously is that you must be over sixteen years of age to visit, but those who do go there will find that the staff consists entirely of young boys about twelve and under who're distinctively pre-pubescent (though not necessarily lacking in musculature). Of course most people don't realize this until they get there.
The resort has all the amenities you could think of, and even some that you wouldn't think of.
(In case you haven't guessed this is primarily age regression, and transgender for girls. Other transformations can occur after becoming a young boy, because nobody's the same, no matter how old.)