The embodiment of the invention relates to a navigation device and a method thereof. The navigation device comprises memory sections (230; 306) and a searching route module (490). The memory sections store map information. The map information contains information for identifying multiple potential positions. Each potential position is corresponding to the potential of a predetermined type of a location which potentially might be found. The searching route module is arranged to determine a searching route of at least one of the visited potential locations. Determined application of the searching route is based on predetermined efficiency measurement of the possibility of finding the predetermined type of location.