The height of existing lighthouses is expressed in two measures: the height of the tower itself, and the distance from the focal plane (that is, the center) of the light source to the water. The latter can be much greater than the former if the light stands on a promontory. Several structures which have functioned as lighthouses exceed the height of any entry in this list, among them the Statue of Liberty at 305 feet (93 m) and Perry's Victory and International Peace Memorial at 352 feet (107 m). These are not listed because they were not constructed as lighthouses per se.