Burlington hosts the Snake Alley Criterium, one of the most physically challenging races in the Midwest. The annual event is held on a 15-block course, with differences in elevation from 555 feet to 678 feet. The course is entirely on city streets, mostly in the downtown commercial area. A one-block-long climb is on the historic brick street named Snake Alley. The 276-foot-long Snake Alley has five switchbacks in a 60-foot climb. The average grade is 12.5 percent in that one block.