A nice blog post comparing maps vs. landmarks as wayfinding techniques, Cognitive Daily: Different ways of finding your way, based on the published article:
Fields, A.W., & Shelton, A.L. (2006). Individual skill differences and large-scale environmental learning. Journal of Experimental Psychology: Learning, Memory, and Cognition, 32(3), 506-515.
Apparently maps are superior to landmarks for learning (according to this experiment).
Having been in Japan last week, it would be nice if all the maps actually were oriented the same way, (i.e. North is up), rather than the apparently random orientation they seem to have.