About 1,000 people a day are braving the cold—and not-completely-immobile ice—to see a rare and spectacular sight: the Apostle Island Ice Caves on Lake Superior. For the first time in five years, it's possible to walk across the ice to the caves, reports Wisconsin Public Radio. The National Park Service describes the caves as a "fairyland of needlelike icicles" with "pillars of ice," and formations that change daily.
"For most people, walking on a frozen Great Lake is just a remarkable experience psychologically, let alone physically," says the site's superintendent. "Sometimes you can even feel the ice move a little bit." Once inside, "You’re looking at these beautiful rock formations, but they’re covered by stalactites and stalagmites made of ice." He believes the caves will be accessible for six weeks, but warned that conditions could change within days. If you can't make the trip yourself, Esquire has a beautiful image gallery.