The plans to open up the large network of Cold War tunnels under Holborn have taken a technical but important step forward to being opened to the public.

Built during WWII as shelters from bombs but never used by the public, the tunnels were converted into deep-level telecoms exchanges during the Cold War. When details about them emerged, they became rather legendary in the subterranean world.

In 2023, the fund manager Angus Murray bought the tunnels to conserve their history while also opening them to the public as a tourist attraction he expects will be “as iconic as the London Eye”.

Although there was an agreement to open the tunnels, and planning permission had been granted, signing the necessary legal papers takes time. The company he set up to run the project, The London Tunnels, says it has now formally acquired the leasehold title to the Kingsway Exchange Tunnels and two surface-level entrance buildings.

At the same time, a previous agreement for a 100-year lease on the tunnels and surface buildings has been extended to 125 years. Until now there’s always been a slight technical chance that the project wouldn’t secure legal title and be able to open the tunnels up as planned. Now they can proceed with the refitting work.

In a statement, the company said that this “marks a significant milestone in the Company’s journey to transform the Tunnels into a major tourist attraction targeting up to 3 million visitors per year, offering a combination of historical heritage experiences and a cultural, multi-sensory, digital experience all within the permitted planning use.”

When it opens, the main entrance will be on Furnival Street, reusing an existing shaft down to the tunnels with a secondary entrance on High Holborn, mainly for schools and people visiting a subterranean bar.

The current plans intend to open the Cold War tunnels in 2027.