Like the 10K and 5K races, runners start the out-and-back course for the XTERRA Trail Run World Championship 21K at the Kaaawa Valley base camp. From there, they’ll follow hard-packed dirt roads and mountain trails that climb more than 400 feet in the first mile and a half; that’s followed by some steep downhills as you head into the remains of the set used for the filming of the 2012 movie “Journey 2: The Mysterious Island.”
(MORE: XTERRA Trail Run World Championship Half Marathon event details)