Palm Springs – This desert resort town some 100 miles east of Los Angeles, in the sprawling Coachella Valley, is known for many things: Its spectacular setting, nestled next to towering Mount San Jacinto; its vibrant gay and lesbian community (fully 100 percent of the City Council identifies as LGBT); and its midcentury modern architecture. It’s also known, perhaps above all, as a haven for old people: The median age here is about 54, compared with 36 for the rest of California.