Early world maps

The earliest known world maps date to classical antiquity, the oldest examples of the 6th to 5th centuries BC still based on the flat Earth paradigm. World maps assuming a spherical Earth first appear in the Hellenistic period. The developments of Greek geography during this time, notably by Eratosthenes and Posidonius culminated in the Roman era, with Ptolemy's world map (2nd century AD), which would remain authoritative throughout the Middle Ages.

Since Ptolemy, knowledge of the approximate size of the globe allowed cartographers to estimate the extent of their geographical knowledge, and to indicate parts of the globe known to exist but not yet explored as terra incognita. With the Age of Discovery, during the 15th to 18th centuries, world maps became increasingly accurate; exploration of Antarctica and the interior of Africa was left to the 19th and early 20th century.

Antiquity

Babylonian Imago Mundi (c. 600 BCE)

A Babylonian world map, known as the Imago Mundi, is commonly dated to the 6th century BCE. The map as reconstructed by Eckhard Unger shows Babylon on the Euphrates, surrounded by a circular landmass showing Assyria, Urartu (Armenia) and several cities, in turn surrounded by a "bitter river" (Oceanus), with seven islands arranged around it so as to form a seven-pointed star. The accompanying text mentions seven outer regions beyond the encircling ocean. The descriptions of five of them have survived:

World map

A world map is a map of most or all of the surface of the Earth. World maps form a distinctive category of maps due to the problem of projection. Maps by necessity distort the presentation of the earth's surface. These distortions reach extremes in a world map. The many ways of projecting the earth reflect diverse technical and aesthetic goals for world maps.

World maps are also distinct for the global knowledge required to construct them. A meaningful map of the world could not be constructed before the European Renaissance because less than half of the earth's coastlines, let alone its interior regions, were known to any culture. New knowledge of the earth's surface has been accumulating ever since and continues to this day.

Maps of the world generally focus either on political features or on physical features. Political maps emphasize territorial boundaries and human settlement. Physical maps show geographic features such as mountains, soil type or land use. Geological maps show not only the surface, but characteristics of the underlying rock, fault lines, and subsurface structures. Choropleth maps use color hue and intensity to contrast differences between regions, such as demographic or economic statistics.