Into the belly of a glacier

Dropping into an ice cave is like entering another world: There's no wind, no ambient sound, and no discernible smell—unless you're eating a peanut butter sandwich; then the scent tends to overwhelm the cold, dark space. Headlamps light up sparkling rooms of ice crystals, towering waterfalls, and narrow passages, while heavy ski boots leave footsteps behind where no other human has ventured.