The Mont Blanc Marathon weekend takes place in Chamonix every year at the end of June. For two days Chamonix is host to runners from all over the world who come to take part in the various races.
The highlight of the event is the Marathon itself. A 42km race that runs from Chamonix centre to Vallorcine on the Swiss border and then back through the Aiguille Rouge nature reserve to finish at Plan Praz (2000m). The shorter Cross du Mont Blanc is a half marathon that follows the same route as the marathon as far as Montroc (just beyond Argentiere), where it then also crosses into the Aiguille Rouge and heads to the finish at Plan Praz.
The weekend also has races for kids with five different classes for different age groups and for those new to cross country running, there is a 10km "discovery" race.