Glena archipelago, France

South of the Brittany peninsula’s tip, some 9 miles (15 km) off Concarneau, the five Glénan islands and their retinue of islets and rocks cluster together on a shallow seabed of pale granite, white sand, and marl, bathed by the Atlantic. This wildly beautiful place with its clear waters, no deeper than 6.5 feet (2 m) at low tide, attracts many yachts. It is also home to France’s most famous sailing school, Les Glénans, founded in 1947, and its parade of trainees in summer. But its most distinguished inhabitant is the Glénan narcissus, which grows on the archipelago and nowhere else. However, the white corollas of this flower were almost decimated by the abundant gulls, thorn bushes, and ferns. The nature reserve on the island of Saint Nicolas was set up in 1974 to ensure the species’ survival, and led to an increase in the number of flowering stems from 6,500 in 1985 to 120,000 in 1998. The fragile nature of the area also demands measures to minimize the impact of humans, such as ecological sanitation, gathering rainwater, keeping to footpaths, and installing solar panels and a wind turbine for local production of nonpolluting electricity.