Other popular routes on the mountain include the Italian (Lion) ridge (AD+ Difficulty rating) and the Zmutt ridge (D Difficulty rating). The four faces, as well as the Furggen ridge, constitute the most challenging routes to the summit. The north face is amongst the six most difficult faces of the Alps, as well as ‘The Trilogy', the three hardest of the six, along with the north faces of the Eiger and the Grandes Jorasses (TD+ Difficulty rating).