This is a piece that is certainly not going to conform with the two major themes of the day.
It's a little something composed quickly about routine, ruts, and London. The Tyburn triangle was an innovative gallows that could execute 24 people at once, if needed, and was situated where the Marble Arch now stands.
The Tyburn itself was a tributary stream that is now completely covered over from source to outflow into the Thames; it's one of London's lost rivers.
There's probably too many "x the" examples in the piece, which makes it a likely candidate for future revision.