If the saying refers to geographical referents the subject under discussion could be anywhere else in the plenum of referents. The locus might also be in a sheaf of referents conjunctive, congruent, or tangential to said plenum. The meaning of the phrase is dependent upon the definition of the locus within its plenum of fictons.

It's quite like trying to define a point with only two reference points for the definition. "X8 Y5" defines a point on a graph, but the third point is actually the matter of the graph itself, or to put it more succinctly, the medium provides a third point for the message*.

Two points alone would define a line.


*Marshall McCluhan, Understanding Media: the Extensions of Man, 1964.