A navigation system includes an image search unit for searching across an image database by using image data transmitted from an image data input unit, as a search key, a search-result output unit for displaying at least one piece of image data extracted by the search on a display, and a destination determination unit for reading point information corresponding to image data selected by a user from the display and determining the read point information to be a destination. Where information about the location, name, telephone number, zip code, address, and so forth, of a point which the user wants to determine to be the destination is not provided, the point can be searched by using image data including an image of the building or scenery of the point.