The Spa at Ventana Big Sur, An Alila Resort
Ventana Inn & Spa's spa is praised by expert writers. Of the 7 publications tracked on TripExpert, 4 referenced the spa, such as Fodor's, Travel + Leisure and Oyster.
Ventana Big Sur, An Alila Resort 
Fodor's
Travel + Leisure
Oyster
Mr & Mrs Smith
Fodor's "You can sunbathe (one of the pools is clothing-optional), walk in the nearby hills, or pamper yourself with mind-and-body treatments at the Spa at Ventana or in your own private quarters"
Travel + Leisure "Afterward, settle in for a sea-inspired treatment at the spa (be sure to take advantage of the adjoining bathhouses and sun decks, but note—some are clothing-optional)"
Oyster "Situated on more than 200 acres of picturesque oceanfront land, The Ventana Inn & Spa looks like a rustic cabin nestled in the woods -- yet it features 62 luxurious, streamlined rooms with wooden accents, refreshing pops of color, and modern amenities such as flat-screen TVs, iPod docks, and free Wi-Fi"
Mr & Mrs Smith "
The mellow afternoon was capped with a visit to the spa (of course)"
