Remember when you were young and you'd come back from summer camp with striped feet, courtesy of your chunky (and now super-muddy) Velcro sandals? Those tan lines may seem dorky-looking now, but at the time, they had a kind of “cool” factor — they served as proof of a summer well spent, exploring and adventuring out in the sun. Those camp days may be a distant memory now, but with this summer's sandal trends, foot tan lines are not just a thing of the past.