On this 850-acre British Virgin Island, high-end touches (think Frette sheets and four-course dinners prepared by a Nobu-trained chef) plus a low-maintenance ethos (no in-room TVs or telephones; a help-yourself honor bar) equals a luxe Caribbean experience. Guests (limited to a maximum of 32, spread out in 15 cottages) rave about the nature reserve’s pristine acreage, a dozen miles of hiking trails, and seven mostly deserted beaches.