Challenge Almere-Amsterdam is a multi-day triathlon and running event in Almere, Flevoland. Racing centers on the Weerwater and the city’s low, flat ground below sea level. Held in September, it offers a full long-distance triathlon (3.8 km swim, 180 km bike, 42.2 km run), plus middle distance, aqua bike, Junior Challenge, super sprint, kids races, and a standalone marathon.
The swim starts at the Esplanade beside the Kunstlinie, moving counter-clockwise through the Weerwater before the first transition at Lumierepark. The bike course uses wide polder roads, with two laps for the long distance and one for the middle distance. The run begins in Lumierepark, looping through the modern city center around the Weerwater. Long-distance athletes complete an opening 900-meter lap, four 10.1 km laps, and a final 900 meters. The marathon runs alongside the closing stages of the long-distance triathlon, so runners and triathletes share the later race atmosphere.