Oprah.com called Brent Christensen's Ice Castle in Silverthorne, Colorado "a cavernous, surreal-looking place that looks as if it were constructed by an army of icy elves." The original Ice Castle was much smaller than Brent's more recent work, though—it was an ice rink Brent built in his backyard, complete with a cave, an ice slide, and a 20-foot tower. Brent's kids affectionately nicknamed it "The Ice Castle," but it was child's play compared to the palatial sculptures he and his team now build each year.

Scattered across the country, the mazes of towers, tunnels, and caverns are all built from solid ice, one icicle at a time; Brent and his team farm their own icicles for these projects, at a rate of more than 5,000 per day.