The long deep cove on the northeast corner of Jewell Island is a favorite weekend escape for Portland boaters. It can tend to get crowded, but if you get there early and drop the hook, there’s great hiking and beachcombing as well as exploration of the mysterious abandoned towers and tunnels of the WW2 submarine spotting installation. Jewell is a favorite spot for kids to roam about (carefully!) and play hide-and-seek. The Punchbowl on the seaward side is a gorgeous rock-strewn beach surrounded by giant hedges of rosa rugosa (beach roses).