A megacity was a settlement with a particularly large population covering a small area. They consisted of huge skyscrapers. In the year 200000, the Ninth Doctor stated that planet Earth was covered in megacities. This was likely due to the population reaching a massive 96 billion. (DW: The Long Game) From Satellite 5, these megacities were clearly visible from the observation deck. The oceans also seemed to be completely covered by these megacities, suggesting that the megacities were offshore as well as on the landmasses.
