A navigation system that searches for a route to a destination based on stored map data that provides navigation guidance to the destination along the route, including a controller that searches for a first route to the destination as a route to be recommended based on a calculation of a search cost, detects whether the first route includes a curve, changes the search cost for any detected curve, searches for a second route to the destination based on the search cost that has been changed and employs the second route as the route to be recommended instead of the first route.