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...
The new Museum's site also has a very cool view through a window, but it's a view of the passing trains [underground], because historically that building (one of London's markets) had a freight service and of course there's no room to move a railway line under London so even though it hadn't needed a freight service for decades the passenger service over the same rails still exists and you will be able to wave to surprised (if they haven't taken that route before) passengers from inside the museum.
A friend lucked into (there's literally a lottery for popular sites) tickets for the new site in Open House London 2024 and the window existed but wasn't really set up for tourists yet of course.
I'm terrible at keeping secrets so, it was probably a bad idea to let me go on the tour, or, perhaps we should try to have fewer secrets so that I'd remember ?
Well, not quite, these aren't tube trains, they're ThamesLink trains, so it would be a mainline railway station, not a tube station, albeit underground. And they already have more appropriate stops in London.
There is a London Wall Walk, starting at the Tower of London. Text copied from the plaques at the postern: (thanks Google Lens)
>The London Wall Walk follows the original line of the City Wall for much of its length, from the royal fortress of the Tower of London to the Museum of London, situated in the modern high-rise development of the Barbican. Between these two landmarks the Wall Walk passes surviving pieces of the Wall visible to the public and the sites of the gates now buried deep beneath the City streets. It also passes close to eight of the surviving forty-one City churches.
The Walk is 134 miles (2.8km) long and is marked by twenty-one panels which can be followed in either direction. Completion of the Walk will take between one and two hours. Wheelchairs can reach most individual sites although access is difficult at some points.
