I'm writing this blog from Petermann Glacier in northwest Greenland, where a cold katabatic wind is blowing off the ice onto the deck of the Greenpeace ship Arctic Sunrise.

CNN: The story

Die-hards can spend up to 15 hours climbing the glacier's almost vertical north face, but moderate hikers prefer this wind-whipped, 90-minute scramble, where the spectacular views more than compensate for any burning thighs.

BBC: The perfect trip: The Canadian Rockies