Aiguille du Grepon; Traverse of the North Ridge

An area classic since 1881!  The Mummery Crack was probably the hardest single pitch in the world when first climbed, essentially solo, by Albert Mummery's guide, Benedikt Venetz.  

The route is accessed from the mid-station of the Telepherique, as described below.  Climb up the Charmoz/Grepon couloir, taking the right hand branch to its top.  This couloir can be mixed, depending upon conditions.  Once on top of the ridge connecting the Charmoz and the Grepon, its easy to spot the off width which is the Mummery Crack.  Graded anywhere from French 5b to 6b, the difficulty felt about 5.8 to me, and I'm an indifferent off width climber.

The route then follows the N. Ridge, sometimes on the Mer de Glace side, sometimes on the Nantillons Glacier side.  There are many highlights, including a couple of "letter boxes", the Rateau a Chevre (a super cool flake/crack that will have you suspended over the Nantillons Glacier), a gendarme or two, a short rappel or two, and the incomparable Vire aux Bicyclettes; all on beautiful, solid alpine granite.

But wait, an extra bonus is that when you reach the summit you will be in the company of a 4 foot tall statue of the Madonna, apparently man-hauled up there in 1927; and which you will use as an anchor for your first rappel! Continue down the SSW Ridge by downclimbing and rappel back to the Nantillons.

Take the telepherique to the mid-station and follow the path toward Lac Bleu and the Blaitiere.  Past the Blaitiere is the Nantillons Glacier, which is ascended to reach the Charmoz/Grepon couloir.  I'm sure that the Nantillons Glacier has changed considerably since I was there in 1992, and not for the better; so check for real time beta on the best approach and descent.