Here is a back alley off Fleet Street, London EC4.

It is Old Mitre Court. The buildings on the right are 1 & 2 Mitre Court Buildings. They are listed Grade 2. Here’s what Historic England says in the listing:
Early/mid C19. 4 storeys plus basement. Plain classical, south elevation of Portland stone with channelled ground storey and cornice below top floor. Arched passage through centre. Plain, rear elevation of yellow brick with railings and gates.
It’s the “rear elevation of yellow brick” that you see in the picture. There are three gas lamps, at least one of which works. The other two look very rickety.
The buildings, 1 & 2 Mitre Court Buildings, are legal practices, housing Barristers and their associates. A list of the barristers is by the doors. The notice on the pavement says “Inner Temple Treasury Office, Open 10am – 4pm”. This is the office underneath the furthest gas light, the one with the right-angled support above it.
The paving slabs at the bottom of the picture were in fact green, as I have drawn them. It was damp, and there was a coating of moss-type algae on the paving slabs. A saying of my late father was, “The plants will win in the end”. When I see such a green coating on stone, in the middle of the City, I am reminded of his words, and I think he is right.
Eventually I had to stop drawing as the rain came down. The drawing got a bit wet.
Here is work in progress and a map:


Drawing took 1hour 15 mins. Colours used mostly Perinone orange, and Prussian blue, with a bit of burnt umber. Indian yellow for the gas lights. All Daniel Smith colours. Pen is Lamy Safari EF nib, with De Atramentis document (waterproof) black ink.
Later note: Article in Private Eye, Autumn 2021 (Westminster council is removing the Gas Lights)