Every spring, Swiss dairy farmer Béat Piller escorts his 56 cows up the slope of the 6,000-foot Alp Vounetz to a grazing pasture and hand-built stable. They will stay there for the next six months, making milk and cheese every single day. In late autumn, they will descend back down to the valley where his family lives year-round. It’s a routine that has existed for millenia.