At 47 metres, with a range of 60 kilometres, the Créac’h lighthouse on Ouessant is the most powerful in Europe and marks the entrance to the English Channel. Come after dark by bike — bring a headlamp, the road has no streetlights — and lie in the grass while its beams sweep the whole island. By day the headland is strewn with old bunkers. It’s mid-renovation but fully working.