The Great Wall of China is often falsely claimed to be visible from the Moon.
The myth exaggerates the wall’s visibility because, although it is extraordinarily long, most sections are only a few metres wide. From the Moon—about 384,399 kilometres from Earth—the wall is far too narrow for the naked human eye to resolve against the landscape.
One early printed version appeared in an 18th-century letter by English antiquary William Stukeley. The claim was repeated in the 19th century and popularised by Ripley’s Believe It or Not! in the 1930s. Its familiarity has helped turn it into one of the world’s most persistent space-related misconceptions.
The wall can sometimes be photographed from low Earth orbit under favourable lighting and weather conditions, but even astronauts have described it as difficult to distinguish. Roads, rivers and large cities are generally easier to see. “Visible from space” is therefore not equivalent to “visible from the Moon.”