Koppenberg (literally "Heads Mountain") is a 77 m (253 ft) high hill in Oudenaarde, the Flemish Ardennes, Belgium. "Koppen" is an abbreviation for cobblestones which in Dutch slang language are called kinderkoppen, or "children's heads". This climb is part of the route of the Ronde van Vlaanderen professional cycling race and feared by many because of its steepness (22% on the trickiest parts) and because of its cobblestones. This makes the Koppenberg difficult even for top professionals. Quite often, riders slow to the point of losing their balance, especially those at the back of the peloton who have to dismount and scramble to the top on foot.