Relive memories of your childhood playhouse at a treetop hotel. No secret password required—just a reservation.

OUT 'N' ABOUT Cave Junction, Oregon; 800/200-5484;; doubles from $90. On the edge of Siskiyou National Forest, this "treesort" has eight whimsical units. One of them, the Treeplex, comes with its own tepee.

CEDAR CREEK TREEHOUSE Ashford, Washington; 360/569-2991;; from $200. No need to worry about pesky neighbors at this one-bedroom mountain retreat: there's nothing for five miles around.

TROPICAL TREEHOUSE Rincón, Puerto Rico; 541/482-6357;; from $200 for four people. Inspired by the Swiss Family Robinson, Jo Scheer built this three-bedroom rental in Puerto Rico's surfing mecca.

POST RANCH IN Big Sur, California; 800/527-2200;; doubles from $695. For luxury seekers, there's Post Ranch Inn—its seven treehouse rooms are equipped with working fireplaces.