1. A navigation system comprising: a storage interface, configured to: access a travelogue image for depicting an interest point; a control unit, coupled to the storage interface, configured to: generate an extracted interest set including the interest point based on information extracted the travelogue image; generate a travel itinerary including an activity sequence based on the extracted interest set; calculate a navigation route based on the travel itinerary and the extracted interest set for accessing the interest point; and generate an attraction suggestion based on the travel itinerary and the navigation route for recommending an attraction point other than the interest point indicated in the travelogue image along the navigation route.