When your calves cramp from climbing the city’s hills, hop on a Blue and Gold ferry for a half-hour ride ($9) to Tiburon, an upscale bayside enclave, where you can hunt for secondhand Valentino and Chanel at Unique Boutique (1690 Tiburon Blvd.; 415-435-5991), just a few blocks from the landing. Then catch a second ferry ($13.50) to Angel Island, an immigration station turned urban refuge, and watch sea birds and pleasure boats bob on the marina while you nosh on barbecued oysters at the island’s new Cove Cantina. Follow a five-mile path around the island’s perimeter for panoramas of the Marin headlands, the Golden Gate Bridge, and the San Francisco skyline. Then take the ferries back to the city and duck into the Ferry Building Marketplace for a tasting at Ferry Plaza Wine Merchant and a splurge on a ten-ounce round of triple-cream Mt. Tam cheese at the Cowgirl Creamery.