Hors catégorie (HC) is a French term used in stage bicycle races to designate a climb that is "beyond categorization".
The average HC climb in the Tour de France from 2012 to 2016 is 16.1 kilometers long and has a grade of 7.4%.
These were even smaller mountains, which gave 3 points to the cyclist reaching the peak first.
Instead of adding a fifth category, the Tour organisation decided to add a hors catégorie.
The following climbs used in the Tour de France have been ranked "Hors catégorie" at least once.