The MIT Campus Map is located at
http://whereis.mit.edu/

If you are looking for the old (pre-june-2003) campus map, you will find it at http://whereis.mit.edu/bin/map

If you are looking for the really old (pre-1997) campus map, you will find it at http://web.mit.edu/campus-map/map-pre-1997/

Aerial photographs of MIT are available at http://ortho.mit.edu/
(these include the entire Boston area)

Floor plans for MIT buildings are located at http://floorplans.mit.edu/
(these are available only to MIT constituents)