Talk about second chances: In the mid-20th century, the seashore at the northern edge of Fort Bragg, California, was littered with old bottles and broken ceramics. Then the Pacific waves worked their magic. Today, sea glass in luminous shades of amber, aqua, emerald, and pearl shimmers along the curve of Glass Beach in MacKerricher State Park. Eagle-eyed beachcombers may also spot pottery fragments—the delicate blue and white of a Chinese vase or faded roses from a teacup long lost. Pocketing such wonders is tempting but forbidden. Sketch or photograph the sparkling cluster, then leave these treasures for future visitors.