I was thinking about Rome and there is one place that’s a 17th century church, on top of 14th century monastery on top of a 1st century apartment. And if you go to the Forum section it’s visibly below the surface of the current city.
For the fact that the city has been active for thousands of years, how do things end up getting buried? Does that mean the elevation of the city is higher now than it was in 0 AD?
Think of all the heavy equipment needed to clear a city lot in modern urban construction. For ancient construction crews, doing all that by hand was often prohibitively costly—far easier to knock the old building down (if it hadn’t already fallen to earthquake or time), save or sell any valuable cut stone, then level out the rest of the rubble and build directly on top of it. So you’ll often find the original foundation with the lower few feet of the first-floor walls, filled with the rubble of the rest of the building.