A ring of low islands around a turquoise lagoon over white shell sand, with grey seals, and offshore the Pietro Orseolo, a 140m…A ring of low islands around a turquoise lagoon over white shell sand, with grey seals, and offshore the Pietro Orseolo, a 140m Italian cargo ship sunk in 1943, plus a scatter of other wrecks that make this a Breton wreck sanctuary. The Glénan sand is ground shell, not coral, which is why the water reads tropical in cold Atlantic light. The islands hold the only population of the Glénan narcissus in the world. The Pietro Orseolo was a blockade runner carrying rubber from Japan when she was torpedoed and driven ashore. Anchorage: La Chambre, the shallow lagoon ringed by nine islands, is one of the most striking anchorages in northern Europe, Caribbean-coloured water at 47 degrees north. Hazards: Big tidal range and strong streams between the islands; the wreck sites are for experienced divers in cold water. Plus