Surrounded by the majestic Himalaya, Sherpas walk along a stone wall in the verdant hillside village of Namche Bazar, Nepal, a last stop on the way to Mount Everest. In recent years, walls and fir saplings have been positioned around the valley to prevent erosion caused by excessive tree cutting in the past.

(Photograph shot on assignment for, but not published in, the National Geographic book, Our World’s Heritage, 1986)