Imagine hurtling down a narrow, twisting, hilly ice track on skates at speeds up to 50 miles per hour, then trying to go even faster so you can outpace the competitors at your elbow. This is downhill ice cross. Beginning back in 2001, Red Bull has been sponsoring races and a world tour under the name “Red Bull Crashed Ice,” building enormous ice tracks in historic city centers to challenge the racers who train for the sport. The tracks are made of steel scaffolding, topped by wood shaped to the desired curves, covered with flexible mats and a network of tubes filled with cooled fluid like glycol—then water is sprayed onto the whole track, slowly building up a four-inch layer of slick ice. Gathered here are ice cross images from recent years in cities in Europe and North America.