Inside the Nuclear Shelter That Stores Over $100 Million in Bitcoin: Explained

Cryptocurrency owners often hide their assets in cryptographic storage devices or on decentralized exchanges or platforms. However, it is estimated that more than two million Bitcoins have been lost forever because owners forgot the only key to access the cryptocurrency.

Xapo Bank's series of nuclear bunkers to protect its Bitcoins are heavily guarded and virtually impregnable. To enter the bunkers, guests must undergo a comprehensive security check and hand over their phones.

Here's CoinTelegraph editor Gareth Jenkinson's exploration of a nuclear bunker containing Bitcoin.

After handing in their phones, the team boarded a helicopter and flew toward the Alps. The bunker door weighed about 6 tons, was military-style and designed to withstand a nuclear blast. The guards scanned their retinas and entered a private code that was updated every minute before the giant door slowly opened.

The group then moves to a small room where staff wearing goggles and bulletproof vests measure the weight and height of visitors. This data is then automatically linked to the identification card that was issued to visitors at the beginning.

The group then passed through a 30-meter-long stone vault that led to a series of security doors. Behind it was a hallway with safes on both sides, which contained pieces of MPC (Multi-party Computation), a form of encryption that allows multiple parties to evaluate a key, protecting the privacy of customers' confidential information and data.

MPC pieces can be stored in Xapo Bank safes around the world, in undisclosed locations and held by many different entities, no one knows their exact location.

Andrew Mannoukas, chief information security officer at Xapo Bank, is one of the few people allowed into the deepest chamber, and said the safes used are physically secured by being housed in military-grade bunkers to protect against threats like natural disasters or real-world theft.

The nuclear bunker in the Alps was acquired by the company in a joint venture with the Swiss Air Force in the 1980s. Inside, it houses two megawatt diesel generators and a sophisticated HEPA air filtration system that removes contaminants, including toxins and radioactive particles. The bunker does not require air conditioning, instead using an underground lake to cool the servers and rooms. The rooms also have their own escape routes, which are remotely controlled and operated.

Bitcoin is just one of the assets hidden here, Mannoukas said.

Although Xapo Bank did not disclose details about the annual maintenance fee for storing Bitcoin, it said that renting this bunker alone costs millions of dollars per year.