Retreat!

Sandy white beaches, subtropical plants, clear blue water—sound like the British Isles to you? No? Then you haven't visited the Isles of Scilly. The Scillys consist of about 150 islands and rocks, five of which are home to just over 2,000 Scillonians. There are no crowds, very little crime and only a few roads. Yet Scilly's hub, Hugh Town on St. Mary's, is less than three hours by boat from Penzance or a 15-minute airplane ride from Land's End, both in Cornwall. Once there, vacationers usually hop between the five main islands—Tresco, pictured; St. Mary's, St. Martin's, St. Agnes and Bryher—on...