Ecumenopolis (from Greek: oecumene, meaning "world", and polis "city", thus "a city made of the whole world"; pl. ecumenopolises or ecumenopoleis) is the hypothetical concept of a planetwide city. The word was invented in 1967 by the Greek city planner Constantinos Apostolou Doxiadis to represent the idea that in the future urban areas and megalopolises would eventually fuse and there would be a single continuous worldwide city as a progression from the current urbanization, population growth, transport and human networks. According to Doxiadis, it was the fifteenth level of ekistic units and the most significant one as the uppermost echelon of the classification. This concept was already current in science fiction in 1942, with Trantor in the Foundation series. When made public, Doxiadis' idea of ecumenopolis seemed "close to science fiction", but today is "suprisingly pertinent" according to geography researchers Pavle Stamenovic, Dunja Predic & Davor Eres, especially as a consequence of globalisation and Europeanisation.
Doxiadis also created a scenario based on the traditions and trends of urban development of his time, predicting at first a European eperopolis ("continent city") which would be based on the area between London, Paris, Rhine-Ruhr and Amsterdam. In 2008, the Time-coined Nylonkong to link New York City, London, and Hong Kong as the eperopolis of the Americas, Euro-Africa and Asia-Pacific.
Before the term had been created, the concept had been previously discussed. The American religious leader Thomas Lake Harris (1823-1906) mentioned city-planets in his verses, and science fiction author Isaac Asimov used the city-planet Trantor as the setting of some of his novels. In science fiction, the ecumenopolis has become a frequent topic and popularized in 1999 by the planet Coruscant in the Star Wars universe. The concept has been explored in the video game Stellaris, where players are given the option of transforming a planet into an Ecumenopolis, providing large amounts of resources to the civilization who controls it. The first three novels by William Gibson are also known as "The Sprawl Trilogy", the "sprawl" being the slang expression for the Boston-Atlanta Metropolitan Axis, or BAMA, where some of the novels events are set. BAMA is essentially one huge city stretching down the eastern coast of the United States, comprising the merged metropolises of Boston, New York, Newark, Washington D.C., Baltimore, Richmond and Atlanta.