Feeling tickled when it comes to mountain summits? Ultra Trail des 4 Massifs is your best shot for an express tour of Chartreuse, Belledonne, Oisans and Taillefer mountain ranges – as long as you are fit enough to climb them up and down in a row! This now mythical trail run gathers above a thousand participants, whether they are mountain lovers, passionate runners – and all a bit adventurous! A complete laid-off and friendly atmosphere is mandatory to counter the required effort and altitude gain (10 000m of altitude gain in a 160km run). UT4M is the only Ultra Run in the world to circle a city and its surroundings – a must-do to spice up your summer !