Cue up John Lennon and imagine a place with no tan lines. It’s nature au naturel at the Sequoians Club in Castro Valley, which promises a fun, family-friendly nudist experience in a beautiful setting. A day at the resort, sans clothing, is $25 (free for members, $10 for first-timers bearing coupons from the Web page). Once there, you can strip away all those artificial, societally imposed layers and get down to the beautiful true personality within. Whether that means sipping a drink and reading by the pool, playing a spirited game of basketball, or taking a five-mile hike to the Castro Valley ridgeline, the club has you covered. It sprawls over eighty acres of rolling hills and valleys, and its trails run up to the borders of regional parkland (where, alas, clothes must go back on). So strut out for a stroll through the picturesque oak trees and green hills with your own Adam or Eve. Hiking shoes are optional, but watch out for poison oak — nothing ruins utopia like full-body blistering.