Tower Subway and London's Lost Tunnels

Published 28 September 2026 · By the Guide to London editorial team · Editor: Terje Moy

You cannot go into Tower Subway, and nobody has been able to since the company that built it sold up and dissolved itself in 1897. What is left at street level is a small round brick structure on the pavement at Tower Hill, a few metres from the crowds queuing for the Tower of London, which almost everybody walks past without a glance.

Tower Subway is a narrow iron tunnel under the Thames from Tower Hill to the Southwark bank, bored in 1869 and 1870. It is usually described as the world's first tube tunnel, and for a short time it carried a cable-hauled car through the iron tube before the money ran out and it became a foot tunnel with a toll. Tower Bridge, which opened in 1894 and charged nothing, finished it off.

Because there is nothing to visit, this page does the only useful thing available: it tells you what the archives actually record, which is a great deal more precise than the version that circulates, and then takes you round the other tunnels under London that are shut, and the three you can still walk through.

What there is to look at above ground

The visible remnant is the northern entrance building: a squat circular structure in brick on the pavement at Tower Hill, a short walk from the Tower Hill Underground entrance and from the Tower of London ticket office. Cut lettering on it names the subway and the London Hydraulic Power Company, which is the clue to everything that happened to it after 1897.

It is not a listed building. We checked the National Heritage List for England's own open data against a 330-metre box centred on the spot, in both the listed-building and the listed-building-polygon layers, and there is no entry for it. Forty-three listed structures came back inside that box, from the White Tower down to a K6 telephone kiosk outside the Byward Tower, and the subway entrance is not among them. That is worth knowing: it has no statutory protection at all.

The paper trail, which is unusually complete

Almost nothing survives to be seen, but the documents survive in quantity, split between The National Archives at Kew and The London Archives in Clerkenwell. Laid out in order they tell a much better story than the tunnel does.

Two things jump out of that list. The company needed a fresh Act to raise more capital within about a year of opening, which is what a venture in trouble does. And the papers about the tunnel run on to August 1962, long after the last member of the public walked through it.

A fireman, a lift and 23 June 1870

The single most specific human detail in the whole file is a Board of Trade accident report. On 23 June 1870 a fireman using the subway lift was hurt badly enough for the accident to be reported and investigated, and the report is catalogued twice in the railway inspectorate's papers at Kew.

The date matters. It falls weeks before the tunnel opened to the public, which tells you that the lifts at the two shafts were working, and being used, while the thing was still being finished. Those lifts, and the cable-hauled car between them, were the expensive part, and they were also the first part to be abandoned.

The 1876 plan to drive a road under the river

In the parliamentary session of 1875-76 a scheme was deposited to build a carriage road under the Thames, with approaches, and to buy and improve Tower Subway as part of it. The engineers named on the plans are F. S. Gilbert and J. H. Greathead.

Greathead is the name to notice. He is the engineer whose tunnelling shield made deep tube work practical, and who oversaw the building of the City and South London Railway, now part of the Northern line. The 1876 scheme was never built. Had it been, the whole geography of the river crossings east of London Bridge would be different, and Tower Bridge might never have been needed.

1897: an Act of Parliament to sell a tunnel

The end is unusually well documented, because it took a private Act. Local Act 60 and 61 Victoria, chapter xcvii, of 1897 is described in the parliamentary record as an Act "to enable the Tower Subway Company to sell their Subway under the Thames from Tower Hill to the opposite side of the River and to dissolve the Company".

The buyer was the London Hydraulic Power Company, which ran high-pressure water mains under the streets to drive lifts, cranes and theatre machinery across central London. Its own schedules of title deeds list Tower Subway among its properties alongside pumping stations and depots. A tunnel under the river was exactly what a company laying mains across it needed.

Within a year, papers in the London Archives record two water companies negotiating over a main in the subway. What it carries in 2026 is another matter: no utility or public body we could find publishes that, so treat any confident statement about its present contents, including ours, with suspicion. What is certain is that it is in use, in private hands, and closed.

The other tunnels under London you cannot get into

Tower Subway is the most complete of a set. These are the ones people most often ask about, with what is actually true about each.

• The Kingsway tram subway. The cut-and-cover tunnel that took trams under Holborn from 1906 to 1952. Its northern section, at the Southampton Row ramp, is listed at Grade II and has been since 11 February 1998; the ramp is visible from the street and closed by a gate. The southern end under the Strand was rebuilt out of existence.
• Mail Rail. The Post Office's driverless underground railway between Paddington and Whitechapel, shut in 2003. A short stretch is open as a ride, which is the exception that proves the rule; our guide to the Postal Museum and Mail Rail covers it. The rest is sealed.
• The deep-level shelters. Eight pairs of parallel tunnels built beneath Tube stations in the Second World War. They are not open, and the entrances are the plain drum-shaped blockhouses you can spot beside Clapham South and Belsize Park stations.
• Disused Tube stations. Down Street, Aldwych, the old Charing Cross Jubilee platforms. Access is by occasional paid tour from the transport museum and by no other route; our page on the London Transport Museum explains how those are sold.

Three Victorian tunnels you can walk through today

If the appeal is the brickwork and the air of a nineteenth-century hole under a city, three are open and two of them are free every day.

The South Kensington subway. The long pedestrian tunnel from the station to the museums is a listed building in its own right, Grade II since 4 April 2006, and thousands of people use it daily without noticing. Walk it slowly on the way to the Natural History Museum and look at the tiling and the ventilation.

The Greenwich and Woolwich foot tunnels. Both free, both open around the clock, both built to get dockworkers across the river. Our guides to the Greenwich foot tunnel and to the Woolwich Ferry and the foot tunnels cover the lifts, the stairs and the hours.

The Crystal Palace Subway. The finest interior of any of them, and the hardest to get into: free open days a few times a year, booked in advance. It is the one that rewards the effort.

Brunel's Thames Tunnel at Rotherhithe belongs in this list too, with a qualification. You cannot walk it, because trains use it: it carries the London Overground's Windrush line between Wapping and Rotherhithe, and you pass through it on an ordinary fare. The Brunel Museum at the Rotherhithe shaft is where you go to understand what you just rode through, and the shaft chamber itself is sometimes open.

Building half a day around a building you cannot enter

Nobody travels to Tower Hill for a brick drum. Treat it as thirty seconds on a route you were walking anyway. From the subway entrance it is a couple of minutes to All Hallows by the Tower, about ten to the Monument, and about twenty on foot across Tower Bridge into Bermondsey, the side the subway's southern shaft came up on.

There are more no-cost curiosities of this kind in our round-up of free things to do in London, and the BT Tower is the other London landmark you can look at and not go up.

Frequently asked questions

Can you visit Tower Subway?

No. It has been closed to the public since 1898 and has been privately owned since an Act of Parliament allowed the Tower Subway Company to sell it in 1897. It is a services tunnel, not a heritage site, and there are no tours, open days or arrangements of any kind for going inside.

Was Tower Subway really the first tube tunnel in the world?

That is how it is normally described, on the grounds that it was the first tunnel driven through London clay with a circular shield to form an iron tube. Brunel's Thames Tunnel at Rotherhithe is older, from 1843, but it was built with a rectangular shield and is not a tube in that sense.

Where exactly did Tower Subway run?

From Tower Hill on the north bank to the opposite side of the river, according to the wording of the 1897 Act that authorised its sale. The Act says nothing more precise than that. The southern shaft is generally placed off Tooley Street in Southwark, which would put the crossing between London Bridge and Tower Bridge.

Why did Tower Subway close to pedestrians?

Tower Bridge opened in 1894 and charged nothing to walk across. A tunnel that charged a toll, reached by ladders or a lift at each end, could not compete with a free bridge in daylight a few hundred metres away, and it stopped taking passengers in the late 1890s, around the time the company sold it.

Is the Tower Subway entrance building listed?

No. Historic England's National Heritage List data returns no listing for it, either as a point or as a polygon, in a 330-metre box around Tower Hill, although forty-three other structures in that box are listed. It therefore has no statutory protection, despite being the only visible trace of the tunnel.

Sources

• The National Archives - Local Act 60 and 61 Victoria c. xcvii, Tower Subway, 1897 (checked September 2026)
• The National Archives - RAIL 1053/59/138, report on an accident of 23 June 1870 involving the subway lift (checked September 2026)
• The National Archives - Thames (Tower) Tunnel plans and sections, session 1875-6 (checked September 2026)
• The London Archives - B/GH/LH/03/022A, Tower Subway papers including the 1897 conveyance to the London Hydraulic Power Co (checked September 2026)
• Historic England - Kingsway Tram Subway, northern section only, list entry 1378792 (checked September 2026)
• Historic England - South Kensington Subway, list entry 1392462 (checked September 2026)