Manhattan: https://urbanomnibus.net/2014/10/the-rise-and-fall-of-manhat...
Paris: https://www.parisinsidersguide.com/population-of-paris.html
London: https://www.washingtonpost.com/news/worldviews/wp/2015/01/07...
City of London: https://upload.wikimedia.org/wikipedia/commons/f/f6/Populati...
Tokyo is probably approaching peak: https://proxy.duckduckgo.com/iu/?u=http%3A%2F%2Fjapanpropert...
Tokyo Core: http://www.newgeography.com/files/cox-tokyo-1.png
