What is randoner?

As an AI language model, I am unfamiliar with the term "randoner". However, based on my research, the term may refer to randonnée, a long-distance cycling or hiking event that originated in France. It typically involves covering a distance of over 200 km or more in a single day or several days, and participants must navigate along a specific course while carrying their own supplies. Randonnée events can be competitive or non-competitive, with participants collecting stamps or other mementos at control points along the way. It is a popular activity among outdoor enthusiasts and endurance athletes.