In the early 1920s you would fly your death trap airliner over Croydon Airport at 2000 feet. Look at the signals square, a large piece of grass next to the control tower, and decode from the signs and arrows, (which are big and placed in the signals square by ATC, no radio communication back then,) which direction to land in, what direction the circuit was to be flown etc then descend into the circuit.
Alternatively you could descend in cloud using the chimney smoke from Croydon Power Station as a navigational fix and land on top of a house on the Purley Way.
I don’t believe I have ever seen an active signals square. Never seen a tethered airship at night either.