Inside Royal Family's secret escape tunnel that left palace 'livid' after it was exposed

For many years, it has been rumoured that beneath some of the royal residences, there are tunnels that the House of Windsor can use to move around secretly, or even escape from danger.

Tunnels underneath historic buildings have often existed, and over the years, the presence of some has gradually been confirmed.

For instance, a secret passageway from one of the Buckingham Palace state rooms, hidden behind a floor-to-ceiling golden mirror, provides an incognito way for the monarch to get to their private apartments and has even been included in tours of the iconic royal residence.

However, when one secret passageway was made public, palace officials were said to be "livid" that people outside the royal circles had been made aware of it.

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"Senior courtiers are livid," and "They consider the tunnel’s existence classified - it was never meant for public knowledge," a palace insider told news publication Page Six.

The private tunnel in question is reported to run from St. James's Palace to the lavish Stafford Hotel, and was previously used by the late Queen when she wanted to go for a "quiet lunch" without being noticed by anyone.

According to the report, the royals don't actually get much use out of the secret passageway anymore, with the luxury hotel instead using it as a spot to store their wine collection and host private dinners.

Princess Eugenie's husband, Jack Brooksbank, let slip that the secret tunnel did indeed exist a few years ago, telling a member of the press, "I haven’t used it yet, but I’d love to check it out."

A few years ago, an ancient secret tunnel at another far older royal residence, Windsor Castle, was revealed.

In a BBC documentary, Fiona Bruce revealed the existence of a "medieval" tunnel route out of the castle.

She explored a seemingly normal-looking room in the castle, explaining: "This is an office just tucked away in a corner of Windsor Castle. But look under here."

She then lifted the carpet and revealed a wooden trap door that provided access to the historic tunnel, "As if by magic," she said, "just lift these and the medieval castle emerges."

Fiona explained that this tunnel has its roots in Windsor Castle history as a fortress, saying: "If you're a soldier in Windsor Castle under siege you need a way to get out.

"And this is the secret passage. This is exactly what it looked like in the 1200s. It's wide enough to accomodate a whole army of men."