Possibly the best mountaineering route in the country! III, 5.3, AI2.
The route climbs the Mill's Glacier, moderate snow or ice on Lamb's Slide, traverses the Broadway ledges for a 1000', then winds its way along the left side of the Diamond with tremendous exposure for another 1000' past features bearing names like the Giant's Staircase before stepping out over the Diamond to join the Homestretch of the Keyhole Route.
With very careful routefinding, the difficulty never exceeds 5.3, but the route tests all your mountaineering skills.
If it still sounds too easy, try it in winter, for a completely different and challenging experience.
...By John Bicknell, Colorado Mountain School