Geoglyphs: Worldwide Ancient Art of the Landscape

Enormous Ancient Drawings Carved Out of the Landscape

Aerial View of Hummingbird Geoglyph, Nazca Lines
Aerial View of Hummingbird Geoglyph, Nazca Lines. Tom Till / Photographer's Choice / Getty Images

A geoglyph is an ancient ground drawing, low relief mound, or other geometric or effigy work that was formed by humans out of earth or stone. Many of them are enormous and their patterns cannot be fully appreciated visually without the use of aircraft or drones, yet they are found in isolated places throughout the world and some are thousands of years old. Why they were built remains a mystery: purposes attributed to them are almost as varied as their shapes and locations. They could be land and resource markers, animal traps, cemeteries, water management features, public ceremonial spaces, and/or astronomical alignments.

What is a Geoglyph?

  • A geoglyph is a human-made rearrangement of the natural landscape to create a geometric or effigy form.
  • They are found the world over and are difficult to date, but many are several thousands of years old.
  • They are often very large and can only be visually appreciated from high above.
  • Examples include the Nazca lines in South America, the Uffington Horse in the UK, Effigy Mounds in North America, and Desert Kites in Arabia.

What is a Geoglyph?

Geoglyphs are known across the world and vary widely in construction type and size. Researchers recognize two broad categories of geoglyphs: extractive and additive and many geoglyphs combine the two techniques.

  • Extractive geoglyphs (also called negative, "campo barrido" or intaglio) involves scraping away of the top layer of soil on a piece of land, exposing contrasting colors and textures of the lower layer to create designs.
  • Additive geoglyphs (or positive or rock alignments) are made by gathering materials and piling them on the soil surface to create the design.
The Uffiington Horse Geoglyph, Oxfordshire, England
This 365-foot-long (111 m) silhouette of a horse carved into the chalky side of a hill in the county of Oxfordshire, west of London, stands out clearly downhill from the ruins of Uffington castle. HOPE PRODUCTIONS/Yann Arthus Bertrand / Getty Images

Extractive geoglyphs include the Uffington Horse (1000 BCE) and the Cerne Abbas Giant (a.k.a. the Rude Man), although scholars typically refer to them as chalk giants: the vegetation has been scraped away revealing the chalk bedrock. Some scholars have argued that The Cerne Abbas Giant—a big naked guy holding a matching club—may be a 17th-century hoax: but it's still a geoglyph.

Australia's Gummingurru arrangement is a series of additive rock alignments which include animals effigies of emus and turtles and snakes, as well as some geometric shapes.

The Nazca Lines

Aerial View of Hummingbird Geoglyph, Nazca Lines
Aerial View of Hummingbird Geoglyph, Nazca Lines. Tom Till / Photographer's Choice / Getty Images

The term geoglyph was likely coined in the 1970s, and it was probably first used in a published document to refer to the famous Nasca Lines of Peru. The Nazca Lines (sometimes spelled Nasca Lines) are hundreds of geoglyphs, abstract and figural art etched into part of the several hundred square kilometers of the Nazca Pampa landscape called the Pampa de San José in coastal northern Peru. Most of the geoglyphs were created by people of the Nasca culture (~100 BCE–500 CE), by scraping away a few inches of rock patina in the desert. The Nazca lines are now known to have been begun in the Late Paracas period, beginning about 400 BCE; the most recent date to 600 CE.

There are more than 1,500 examples, and they have been attributed to water and irrigation, ceremonial activity, ritual clearing, concepts of radiality like those expressed in the much later Inca ceque system, and perhaps astronomical alignments. Some scholars such as British archaeo-astronomer Clive Ruggles think some of them may be for pilgrimage walking—deliberately constructed so that the people could follow the path as they meditate. Many of the geoglyphs are simply lines, triangles, rectangles, spirals, trapezoids, and zigzags; others are complex abstract line networks or labyrinths; still others are spectacular humanoid and plant and animal shapes including a hummingbird, a spider, and a monkey.

Gravel Drawings and the Big Horn Medicine Wheel

One early use of geoglyph referred to a wide variety of gravel ground drawings at the Yuma Wash. The Yuma Wash drawings are one of several such sites found in desert locations in North America from Canada to Baja California, the most famous of which are the Blythe Intaglios and the Big Horn Medicine Wheel (built ca. 1200–1800 CE). In the late twentieth century, "geoglyph" specifically meant ground drawings, especially those made on desert pavements (the deserts' stony surface): but since that time, some scholars have broadened the definition to include low-relief mounds and other geometric-based constructions. The most common form of geoglyph—ground drawings—are in fact found in almost all of known deserts of the world. Some are figural; many are geometric.

Big Horn Medicine Wheel
Native American Geoglyph in Wyoming.  Christian Heeb / Getty Images

Native American Effigy Mounds

Some North American Native American mounds and mound groups could also be characterized as geoglyphs, such as the Woodland period Effigy Mounds in the upper Midwest and Great Serpent Mound in Ohio: these are low earthen structures made in the shapes of animals or geometric designs. Many of the effigy mounds were destroyed by farmers in the mid-19th century, so the best images we have are from early surveyors such as Squire and Davis. Clearly, Squire and Davis didn't need a drone.

Serpent Mound - Squier and Davis 1846
Plate XXXV from Ancient Monuments of the Mississippi Valley. Great Serpent in Adams County, Ohio. Ephraim George Squier and Edwin Hamilton Davis 1847

Poverty Point is a 3.500-year-old C-shaped settlement located on the Maco Ridge in Louisiana that is in the shape of spoked concentric circles. The site's original configuration has been a topic of debate for the past fifty years or more, partly due to the erosive forces of the adjacent Bayou Macon. There are the remains of five or six concentric rings cut by three or four radial aventues around an artificially raised plaza.

Poverty Point, Lousiana
3,000 Year Old Poverty Point Earthwork.  Richard A. Cooke / Corbis Documentary / Getty Images

In South America's Amazon rainforest there are hundreds of geometrically-shaped (circles, ellipses, rectangles, and squares) ditched enclosures with flat centers that researchers have termed 'geoglyphs', although they may have served as water reservoirs or community central places.

Works of the Old Men

Hundreds of thousands of geoglyphs are known in or close to lava fields throughout the Arabian peninsula. In the Black Desert of Jordan, ruins, inscriptions, and geoglyphs are called by the Bedouin tribes who live the Works of the Old Men. First brought to scholarly attention by RAF pilots flying over the desert shortly after the Arab revolt of 1916, the geoglyphs were made of stacks of basalt, between two to three slabs high. They are classified into four main categories based on their shape: kites, meandering walls, wheels, and pendants. The kites and associated walls (called desert kites) are thought to be mass kill hunting tools; wheels (circular stone arrangements with spokes) appear to be constructed for funerary or ritual use, and pendants are strings of burial cairns. Optically Stimulated Luminescence (OSL dating) on examples in the Wadi Wisad region suggest they were built in two main pulses, one in the Late Neolithic about 8,500 years ago and one about 5,400 years ago during the Early Bronze Age-Chalcolithic.

Atacama Geoglyphs

Chile, Region I, Tiliviche. Geoglyphs on a mountainside near Tiliviche, Northern Chile- representations of Llamas & Alpacas
Llama Caravan Geoglyphs, Atacama Desert, Northern Chile. Paul Harris / Getty Images

The Atacama Geoglyphs are located in the coastal desert of Chile. There were more than 5,000 geoglyphs built between 600-1500 CE, made by moving around the dark desert pavement. In addition to figural art including llamas, lizards, dolphins, monkeys, humans, eagles, and rheas, the Atacama glyphs include circles, concentric circles, circles with dots, rectangles, diamonds, arrows, and crosses. One functional purpose suggested by researcher Luis Briones is that of identifying safe passage and water resources through the desert: the Atacama geoglyphs include several examples of drawings of llama caravans.

Studying, Recording, Dating, and Protecting Geoglyphs

The documentation of geoglyphs is performed by an ever-increasing variety of remote-sensing techniques including aerial photogrammetry, contemporary high-resolution satellite imagery, radar imagery including Doppler mapping, data from historic CORONA missions, and historic aerial photography such as that of the RAF pilots mapping desert kites. Most recently geoglyph researchers use unmanned aerial vehicles (UAVs or drones). Results from all of these techniques need to be verified by pedestrian survey and/or limited excavations.

Dating geoglyphs is a little tricky, but scholars have used associated pottery or other artifacts, associated structures and historic records, radiocarbon dates taken on charcoal from interior soil sampling, pedological studies of soil formation, and OSL of the soils.

Sources and Further Information