Esalen Institute, Big Sur, California
Credit: Brown Cannon III / Intersection Photos

Hot springs set on cliffs above the Pacific are what sets Esalen apart from all other retreats. Used for healing rituals dating back 6,000 years to the Esselen Native Americans, the springs are a singular adventure, combining Big Sur's stunning views with an awe-inspiring, 119-degree soak (night bathing, from 1 a.m. to 3 a.m., is $25 and includes silent tubs for meditation). Inhale the salty mist and immerse yourself in the retreat's breathtaking beauty – 120 acres of paradise on a remote coastline. Founded in 1962, Esalen has hosted rebels like Hunter S. Thompson, Timothy Leary, and Jack Kerouac – although these days, you're more likely to spot celebrities like Penélope Cruz or Orlando Bloom blissing out before its panoramic sunsets or taking in daily yoga, meditation, and tai chi classes. Weekend workshop rates include room and board and run the gamut from sleeping-bag accommodations all the way to high-end luxury: the three private cliffside Point Houses. Unlike most of the center, which has no cell coverage, these rooms have Internet access and a landline – as well as private decks with outdoor claw-foot tubs for soaking in the moonlight – for $1,750 a weekend. [From $405 for weekend workshops;]