The smallest and westernmost of the Canary Islands, Hierro is a rugged, windswept place believed in Columbus’s day to be the very western edge of the world. Its picturesque, whitewashed capital, Valverde, is unusually located high in the mountains some distance from the sea, and home to just 2,000 souls. The volcanic island was designated a UNESCO biosphere reserve in 2000, and photographers delig…