San Ysidro Ranch is one of the most exclusive, romantic luxury options in not just California, but the entire country. The grounds are stunningly beautiful, with mountain views, fresh air, and a secluded location in a well-heeled neighborhood. The cottage-style units are individually furnished with stone fireplaces and pour-poster canopy beds; some have private outdoor whirlpool tubs. A chic swimming pool and charming Californian cuisine restaurant set in a flowering garden have attracted everyone from JFK and Jackie to Gwyneth Paltrow and Chris Martin. Some guests argue the experience doesn't justify the high price tags, but for honeymooners or couples, it's undeniably a first-class option.