London's secret wartime tunnels to welcome tourists with spy museum and deepest underground bar

A long-secret network of tunnels under Central London is set to open to the public as a major new attraction, combining military history, spy stories, and a record-setting underground bar. The 90,000 sq. ft. space, located 100 feet beneath Holborn, once housed Britain’s wartime communications and intelligence operations-and now, it’s being transformed into one of the city’s most unique tourist sites.

Approved by local authorities, the site will feature the relocated British Military Intelligence Museum, an interactive World War II memorial, and what its developers claim will be the world’s deepest bar.

A secret built for war

The tunnels were first constructed in 1940 to shelter Londoners during Nazi air raids. Designed to hold up to 8,000 people, they were completed in 1942 — but by then, subway stations had already been repurposed as shelters. Instead, the tunnels became home to the Special Operations Executive (SOE), Britain’s covert wartime sabotage unit.

Naval officer Ian Fleming, who served as a liaison to the SOE, is believed to have drawn inspiration for his James Bond novels from his time in the underground complex. “This truly is the Q Branch of James Bond,” said Angus Murray, CEO of The London Tunnels, which is developing the site.

A hidden cold war hub

After the war, the tunnels expanded into a secure communication hub. In the 1950s, they served as a terminus for the first trans-Atlantic telephone cable and later carried Cold War hotline messages between Washington and Moscow. At its peak, around 200 people worked underground, complete with a canteen and bar. A government bunker for nuclear emergencies was also installed.

By the 1980s, British Telecom left the site, and the tunnels fell out of use. They remained untouched until a private equity group acquired them in 2023.

Museum, memorial and bar

The restored site will host:

• A memorial for 40,000 civilians killed in WWII bombings,
• A relocated and expanded British Military Intelligence Museum,
• Cultural exhibitions,
• And an underground nightspot, billed as the world’s deepest bar.

The museum will highlight over 300 years of British military intelligence, including rarely seen artifacts from the SOE. “A heavy theme... is how do you tell the truth from lies?” said Alistair, the museum board’s chair.

The entrance today is a plain door in an alley, but once inside, visitors walk through dim corridors lined with wartime machinery, a retro bar, and remnants left behind by urban explorers-including, oddly, a bear costume.

The developers aim to open the attraction by 2028 and estimate up to 4.2 million visitors annually. “If you go home and say, ‘I went to this really cool tunnel today,’ we’re halfway there,” said Murray. “If what’s inside is even better, you’ll go, ‘That’s fantastic.’”

(With inputs from AP)