A method of locating difficult access points on a topological map includes: analyzing curvilinear distances using a chamfer mask to catalogue approximate values C(V) of the Euclidean distances separating a point C.sub.00 of the map from its nearest neighbors V; determining therefrom, at each point C.sub.00 of the map of curvilinear distances, the discrepancies |DT(V)-DT(0)| of curvilinear distances separating the point considered C.sub.00 from its nearest neighbors V; comparing these discrepancies with the approximate values C(V); determining the point as a difficult access point based upon a difference between the Euclidean distance and the determined discrepancies of curvilinear distances; and rendering a display of a map indicating difficult to access points.