This local megapolis concept first came into being in 2004.

Globally, there were only a handful of main cities by 1900.

The megapolis concept was first mooted by French geographer Jean Gottman (1915-1994), with a proposal in 1961 to develop the area from Boston to Washington as a megapolis.

India adopted it by first creating Hyderabad, and at the last general election, the BJP promised to build 100 such cities.

Mumbai and Pune are being developed into a megapolis.

With the expansion of the global population, it is projected that half of the world population will live in cities by 2025.

According to Economist magazine, China has 13 megapolis projects, including in Shanghai and Peal River Delta.

The proposed Jing-Jin-Ji megapolis is as big as Kansas City in the US.