Aerial landscape art includes paintings and other visual arts which depict or evoke the appearance of a landscape from a perspective above it—usually from a considerable distance—as it might be viewed from an aircraft or spacecraft. Sometimes the art is based not on direct observation but on aerial photography, or on maps created using satellite imagery. This kind of landscape art hardly existed before the 20th century; its modern development coincided with the advent of human transport which allowed for actual overhead views of large landscapes.