Visitors to legal London may occasionally wonder what lies behind that mysterious concrete frontage at 39 Furnival Street, just off High Holborn. The property has no windows, just a battered steel door bearing the sign ‘Fire exit do not obstruct’. Once upon a time we would have had to kill you for saying this, but we can now safely reveal that the doorway is one of two entrances to a network of tunnels more than 100 feet below the City streets. 

The tunnels, which run deep under Chancery Lane and Holborn, were dug as air raid shelters and a headquarters for wartime spooks Special Operations Executive. During the Cold War they housed, among other things, the telephone exchange handling the hotline between the White House and the Kremlin. Telephone operators and engineers could refresh themselves in London’s deepest bar, presumably only after shifts involving the nuclear trigger.

Now the site is set for a comeback: the City of London has approved plans to convert the complex into a visitor attraction, with a ‘heritage exhibition’ space for cultural events - and, yes, a bar. Obiter is not expecting it to replace our Carey Street watering hole, but we’re looking forward to the 2027 season of law firm parties. Assuming such events are still a thing in 2027, when we’re probably more likely to be invited to orangeade and origami sessions.