The Experimental Spiral Escalator: Holloway Road Tube Station (a beautiful ox-blood red Leslie Green design) holds a massive secret. In 1906, it was chosen as the test site for the world's first spiral escalator built by American inventor Seeberger. It was deemed too dangerous, never opened to the public, and was promptly dismantled. Remnants of it are still stored in the London Transport Museum Depot.
The Ghost Lift Shaft: When the station was constructed, builders dug two massive elevator shafts, but traffic predictions shifted, and only one shaft was ever fitted with working lifts. The other remains an empty, hidden void.
B/W print; two workmen stand on the spiral elevator at Holloway Road station, built by Jesse Reno, 1906.