To provide a navigation system, a navigation method, and a navigation program which can perform guidance to allow a user to easily understand an exit road in an annular intersection in consideration of visibility of the exit road from the annular intersection.

A navigation system 1 comprises: a travel route specification unit 51 for specifying a travel route for a vehicle; a visibility specification unit 52 for, when an annular intersection exists on the travel route specified by the travel route specification unit 51, specifying visibility of an exit road from the annular intersection on the travel route on the basis of presence of constructions in the vicinity of the annular intersection; and a guidance control unit 53 for determining guidance contents about the exit road on the basis of the visibility specified by the visibility specification unit 52.