London was (almost entirely[1]) burned to the ground in the great fire of 1666[2]. The new city was built on the smoldering wreckage of the old one.

[1] Pretty much the only things that survived were the tower of London and a few streets around The Cathedral of St Bartholomew the Great near Smithfield Market which most people even in London don't know about even though hundreds of people pass just one street away every day https://en.wikipedia.org/wiki/St_Bartholomew-the-Great

[2] https://www.london-fire.gov.uk/museum/history-and-stories/th...

Most cities exist where they do for geographical reasons that have existed for longer than humans. Until the railroad (~200 years ago) you couldn't have a large city unless it had a good port as the only possible way to get enough food in to support a city was by boat. There are only limited places that support a great port so once humans start a city we can't abandon it. Today we could abandon NYC - the port itself would have to remain but everything else could move elsewhere (the port could not move elsewhere as most places don't have a way for ships to get in without massive ocean floor projects) - that won't happen because there is so much inertia of people already living there, but it could.

I don't know what the natives in Australia did. however I can report without looking that if they had the numbers to build cities they would be about where the current cities are.

There were massive cities up rivers too with I think no real seafaring component: https://news.ycombinator.com/item?id=37973229

River ports exist. I did not mean to exclude them. Some places on a river are better than others.

I recommend you look into it at your local library.

Cities are dynamic in much the same manner as axe's that have handles and axe heads replaced .. while growing larger and spawing smaller axes about them.

The "Great Fire of London" took out a large chunk of the city which allowed for a clean slate redesign and rebuild of a district - it didn't wipe out the entire city, modern London is vast compared to the original Londinium Fort.

The original quote, as given, was that most cities in the world were built on the implied total ruin of prior cities - I'd argue that relatively few cities (not most) were built on the smoking ruins of near total destruction (74 cities at least in Japan fit the bill, along with roughly that number in Europe) with most having a more organic growth based on a long series of partial rebuilding of districts in rotation.

Thank you for your advice - I did once work on digitising a few hundred years worth of city records some 40 years ago.