A London Inheritance published a post detailing the Tower Subway and also implied the southern end of the subway happened to be a mystery because it could not be ascertained whether the modern structure behind the Unicorn Theatre in Vine Lane was indeed its southern end. Its not its original southern end however the tunnel was extended perhaps around twenty years ago from its original location further north – thus the southern end of the Tower Subway is no mystery of any sort when it comes to deciding whether this is indeed the present access point to that tunnel.
The original access point happened to be at what is now 4 More London Riverside. I have often wondered if that tall tower with its huge lights outside the premises happens to be a ventilation pipe of some sort – since its almost on top of the location where the tunnel originally emerged. If that is the case then indeed there is some indication as to the Tower Subway’s original northern end location. The slightly modified location would no doubt be due to the need to divert any ventilation slightly away from 4 More London itself. The lighting tower (and possibly what doubles as a ventilation pipe) can be seen here on Google Streets. In any event the lighting tower at least seems to be an attempt to mark the historic southern end of the Tower Subway.
Today’s new post – Tower Subway and the Mystery of the Southern Entrance at https://t.co/RQByWuOQcQ pic.twitter.com/aNFofoscqy
— A London Inheritance (@VanishedLondon) May 18, 2025
Its quite well known the tunnel’s present southern end emerges by the Unicorn Theatre. One of the first people to have indicated this fact that happens to be Tim Dunn.
#OTD 2nd August 1870 – London’s Tower Subway, a tiny one-carriage cable-hauled railway beneath the Thames – opens to the public. It was effectively the first “tube” railway. The tunnel now carries cables, but last yr I went hunting & found southern entrance site, off Tooley St. pic.twitter.com/LnKOOiRbCq
— Tim Dunn (@MrTimDunn) August 2, 2022
There was a period of perhaps a day or two in late February 2021 when message got around a number of Urbex explorers the subway entrance Tower Hill was easily accessible. The workers who had been down the tunnels had gone home having inadvertently left the premises unlocked. Evidently those in the know took an immediate opportunity to explore and film the subway and also depict how the tunnels have been extended to a new access point much nearer to Tooley Street – some 95 metres (312 feet) south of the original access point.
Some quick research reveals the London Hydraulic Power Company were intending to build an identical structure in Vine Street to compliment the one at Tower Hill that was built in 1923. (Report from Daily News 30th December 1922 on the proposed modifications being done to the subway). Whether this was done is not known, but in any event it seems as there are no pictures or evidence of such a structure, it seems likely it had not been constructed.
Apart from the video from The Secret Vault (and discussed in my previous post) – which does indeed show the Tower Subway’s new extension underneath More London towards the rear of the Unicorn Theatre in Vine Street, there are other videos too which also show the newer extension to this historic subway. Quite when it was built is not exactly known however it was possibly in the late 1990s or early 2000s just before this part of More London (formerly derelict land to the south of Potter’s Fields) had been built over.
The next video most clearly shows how the southern end of the subway emerges into a modern structure further south and just behind the Unicorn Theatre.
This one from Beno (a noted Urbex vlogger that covers lifts, tunnels, abandoned buildings but also has reviews of various transport systems including trams, buses and trains) very clearly shows how the southern entrance emerges behind the Unicorn Theatre. For that segment of the video go to near the end of the video at 11.39.