The Dentelles de Montmirail massif, which stretches for about five miles (8 km) in length, is renowned in the climbing world for the steep but safe and very adherent walls of its vertically erected limestone slabs. The three parallel chains of the Dentelles - the chain of Grand Travers in the north, the Dentelles Sarrasines in the center, and the chain of Clapis in the south - offer adepts more than 600 equipped climbing routes. Sixty-five to two hundred and ninety-five feet (20 to 90 m) long, their difficulty ranges from 3c to 8b. The site attracts experienced climbers from all over Europe, with foreigners accounting for half of the participants.