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 grab a mooring or 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).