You get to see a ghost of about 3 or 4 squares that are unexplored as you are travelling around, unless they are blocked by a door. Once you have stepped on a square it stays on your map forever. The area map that shows you all your squares only stretches so far though - I would've liked to have been able to see all of the steps I had taken and the world map, while heralding back to the classic world map style for MM, doesn't quite give me that satisfaction.