I learned about the Post Ranch Inn in Big Sur, a heavenly spot on the edge of the earth (or at least the West Coast) from interior designer, Robin Pelissier, who owns a design business and little shop called Robin’s Nest in downtown Hingham, Mass. I had been soliciting suggestions for romantic honeymoon spots for “The Lovers’ Go-To Guide” in the Boston Globe Sunday Magazine’s Valentine Day issue. While Big Sur had always connoted the great outdoors to me (i.e., hiking, bird watching, etc.), I was never much interested. But this is a spa, and an altogether different story.