Megacity

Structure
A mega city, like a city, is a large settlement with a large population covering a small area. A megacity is a city that usually consists of huge skyscrapers often reaching over 200+ floors in height on average. Cities like these are usually purposely built if a population of an area is too high.

In the year 200,000, the Doctor states that planet Earth is covered in Megacities.This is likely due to the population reaching a massive 96 billion (DW: The Long Game). From Satellite 5, these megacities are clearly visible from the observation deck. The oceans also seem to be completely covered by these megacities aswell, suggesting that the megacities can be offshore aswell.