I remember having a flight from LHR to Calgary and was lucky enough to be in a window seat and for it to be daylight and clear - only time I've seen Greenland! What I was prepared for was how big, flat and pretty much featureless that part of Canada is just his awesome patchwork of lakes, streams and the occasional esker.

Only thing that has been similar was flying north from Kenya to Egypt and being similarly amazed at how vast the Sahara is.