The Museum of London site (now closed as they prepare to move to their new site, coincidentally near the AWS HQ), and there was a window you could look down on part of the wall, which you can also see from the other side of the road near Barbican. I won't give directions, as that seems futile anywhere near Barbican, but I had only just thought about how weird it is that there is wall at Tower Hill, and wall at Barbican - they can't be the same run of wall as it was built, can they? That'd be immense...

  London's original wall was 2 miles long, 6 metres high and almost 3 metres thick at its base

Architectural Digest has a good video of the Roman Wall and other Ancient Roman history in london: https://www.youtube.com/watch?v=j_-JnvuAeVI

Not bad engineering to make it through a handful of civil wars, a Blitz, and a couple thousand V-1 rockets mostly intact. You have to wonder how long all the steel and concrete that's been laid around the Thames from our civilization will last.

> ground level then was a few metres lower than now

What?! That's huge. What happened?

For more of this sort of thing, check out the Old Structures Engineering blog. Don does a post a day, day in, day out -- so obviously some are more detailed than others. I enjoy having it in my feed.

Recent examples:

https://oldstructures.com/2025/10/24/not-quite-a-tunnel/ https://oldstructures.com/2025/10/21/relieved/

For another interesting mix of new and ancient, check out the Serdica metro station in Sofia, Bulgaria. [0] It's fully inside an excavated Roman-era ruin. Very cool!

[0] https://en.wikipedia.org/wiki/Serdika_Metro_Station

Note this is about the City of London, an entity much smaller and older than the modern city known as London. It's land area is about 3 km^2.

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

Title should probably read "the City of London" rather than "London".