Four strange places to see London's Roman Wall

> ground level then was a few metres lower than now

What?! That's huge. What happened?

Before industrial demolition was common, old buildings would be town down and material repurposed for new constructions, build on top of existing foundations and rubble. Do this enough over the centuries and your city will slowly rise in height.

Every time a building fell apart due to earthquake, fire, flood, war, abandonment- the good material was taken for reuse and the bad material became rubble which was often smoothed out and used as a foundation.

Shoes. All the way down. ;-)

If anyone’s ever in Barcelona I recommend checking out the history museum, which is literally built on top of some Roman and medieval ruins. You can descend into the basement to see the excavated remains of the foundations of Roman buildings that had been levelled and built on top of.

Seattle: https://undergroundtour.com

Buried ships of San Francisco - https://www.nps.gov/safr/learn/historyculture/buried-ships-o...

https://www.baylightscharters.com/bay-lights-charters-blog/w...

> Delgado received his first big assignment back in 1978 while working for the National Park Service: excavating and studying the remains of the Niantic, one of the first whaling vessels that brought gold-seekers to the area. It had been discovered near the Transamerica Pyramid at the corner of Clay and Sansome streets. After being left behind during the Gold Rush, the ship had been repurposed to serve as a storeship, saloon, and hotel until its demise in an 1851 fire.

Consider that https://maps.app.goo.gl/tYjaESQXss2KhHXQA used to be sea level.

As mentioned else comment, things were torn down and that served as the foundation for the next building.

Takes me back. I don't think we have the number of shoe shops that used to dominate the high street and at the time I assumed inspired Adams.

If you leave ground alone all sort of things grow on it or lay on it. Dirt, mud, leaves etc. Soil grows at about 1 mm per year. 1 meter in 1000 years.

Historically cities were hit by floods and wars and new buildings were built on top of the foundations of old ones. We had an article about that church in Rome built over another roman church built over another roman church, etc. down to an old temple on a spring, or something like that.

It might even happen faster than that. If I don't sweep my cement patio for about a month, the decaying leaves from the bushes are enough to make about an 1/8th inch of fresh brown soil under the leaf piles.

Exactly. This is hard to understand when living in a flat in a modern city but it's immediately clear in any other case.

My figure of 1 mm is about the compacted result of decaying and layering. It may vary a lot according to the configuration of the ground.

Sounds like Basilica of San Clemente[1][2]. One of the many many many "hidden" gems of Rome. Highly recommend visiting it!

Or you can go on a virtual tour[3]

[1] https://www.basilicasanclemente.com/eng/

[2] https://maps.app.goo.gl/zpXpQuxQLUvE5TLA9

[3] https://www.basilicasanclemente.com/eng/a-virtual-tour/

Thanks! And this is the article I remember https://www.exurbe.com/the-shape-of-rome/

Ah I didn't realize it was that fast! I always pictured a few mm per 1k years.

Worms as well.

https://en.wikipedia.org/wiki/The_Formation_of_Vegetable_Mou...