In one aspect, a method for determining a location of a landmark using a map is described. Trajectory data is obtained indicating movement of a device at an area. The trajectory data indicates a landmark. A map is obtained of the area. At least a portion of the trajectory data is compared and/or matched with at least a portion of the map. Based on the matching, a location of the landmark is determined in the map. Various implementations involve system, devices and software relating to the above method.