Masses; tired, huddled or otherwise

There are thirty megacities, scaling down from Tokyo at the top to Tianjin at 10.6 million just squeezing in.
The other Japanese megacity is Osaka at fifteenth position with 16.8 million population.

There are five megacities in China, three in India and two in the United States.

Seventeen capitals are classed as megacities; actually I think I miscounted and its eighteen. Hey, if Wikipedia contributors can do it, so can I.

Megacities not mentioned or referenced in this discussion thusfar include Cairo (16.1 million), London (15.5 million), Buenos Aires (14.5 million), Bangkok (14.5 million), Istanbul (13.8 million), Lagos, (13.2 million)  Tehran (13.2 million), Rio de Janiero (12.9 million), Rhine-Ruhr (12.19 million), Shenzhen (11.7 million) and Paris (10.7 million).

Cities still

After the unsettling certification of a city proper, I've been on a search to see what other categories shine a streetlight on built-up areas. Metropolitan areas are difficult to measure but are roughly designated as including the labor market area and the surrounding commute, with the caveat that the surrounding region must be of minimal agricultural focus, and include a large number of commuters into the main urban area.

Despite this sub-sophistry, the most populated metropolitan areas are much the same as the most populated cities, only in a slightly different order. Tokyo is the largest and the two not figured in 'cities with the highest population' are Mumbai (20,748,395) and Osaka-Kobe-Kyoto (19,342,000)

II

Here's a word you don't hear every day: agglomeration. An agglomeration is a large group or pile of different things, but in an urban planning sense, an urban agglomeration is 'the population contained within the contiguous territory without regard to administrative boundaries or commuter flows' according to Wikipedia. So it does not even have the restriction in definition of a 'metropolitan area'

Urban agglomeration	Population
Tokyo		36,933,000
Delhi NCR		21,935,000
Mexico City		20,142,000
New York-Newark		20,104,000
Sao Paulo		19,649,000
Shanghai		19,554,000
Mumbai		19,422,000
Dhaka		15,391,000
Beijing		15,000,000
Kolkata		14,283,000

III

I was going to condense all the population aggregation into one thread but I've encountered a setback: I've seen my Wikipedia source virtually change before my eyes so what you see is a 'before' snapshot. Okay, maybe I won't attempt conurbation but before I go on with the other significant measures, I need to take stock of what changes have been made around me.

Con dense

Geography is not my strong suit but the real reason I haven't heard of any of these cities beside Manila is because they are parts of a larger urban environment. Indeed, many are either in Metro Manila or Bengal. The distribution is either in India or the Philippines, with the number ten entry being the joker in the packed; being in France.

But, if the Hooghly River features in the background in many of these congested regions, clearly the city category differs from that of a discrete metropolis.

Yokohama has 8,500 people per square kilometre it says at one source; elsewhere a scribe opines how it is difficult to measure the population of Tokyo and produces instead a table that shows the prefectures and their respective densities. I can hazard a guess and say that density when compared to the "cities proper" on the list, is not that bad.

Manila is most crowded and has the sixth highest urban population so we know it's in for a Best of Congest award.

One figure that may rock your world - Titagarh has a tiny population teetering between 114 thousand and 124 thousand. Yes, it's in West Bengal with the second highest density of a city proper.

And France isn't a one-off in the tightly packed stakes as the runner-up with 67,047 people per square kilometre is Le Pre-Saint-Gervais.

Dense city

City	Density (square km)
Manila		42,857
Titagarh		38,337
Baranagar		35,220
Serampore		33,649
Pateros		30,546
Mandaluyong		29,192
South Dumdum		28,984
Kamarhati		28,696
Caloocan		27,916
Levallois-Perret		26,432

Ur ban(e)

The thirty seven million people in Tokyo is a sizeable population by any measure. I'm trying to comprehend a city ten times the size of the one I move through. An urban population that outstrips that of countries.

All the cities on the post have populations of over twenty million people. Imagine the infrastructure; the plumbing, the power supply

I was fifteen when I was in Jakarta last so I can't sensibly give insight into this city but nearly twenty seven million people can.

It was the first time I'd heard of the couplings of a couple of these cities, or the alternate names.

I think people are vaguely aware that there is an Old Delhi but it doesn't get as much mention despite its dimension.

New York City has been mythologised to within an inch of its life but we don't hear as much from Karachi. Lo, those who dwell in Valley of Mexico.

Metre o' Polis

I don't want to mince words over municipalities. Set my sites in the city side for the largest population.

Tokyo-Yokohama
Jakarta
Seoul-Incheon
Delhi
Shanghai
Manila
Karachi
New York City
Sao Paulo
Mexico City