EXCLUSIVE: I worked construction on New York City’s mysterious windowless building – here’s what I saw

Nestled in the heart of Lower Manhattan, the mysterious 33 Thomas Street, commonly known as the “Windowless Building,” has been shrouded in secrecy for decades.

This formidable skyscraper, windowless and 170 meters high in the skyline, has puzzled New Yorkers and intrigued passersby since its completion in 1974.

Often considered one of the city’s strangest buildings, its true purpose has long been the subject of intrigue and speculation.

One man, who asked to remain anonymous for security reasons, worked with his son as a steamfitter — someone responsible for installing wiring and pipes that carried high-pressure liquids and gases — in the building in the early 2000s.

His son told Dailymail.com that his father and crew were strictly prohibited from entering certain rooms in the building. There were parts of the building that were not accessible to all visitors. No one was allowed to enter.

‘There were rooms we couldn’t get into. “They specifically told us we weren’t allowed in, and we couldn’t ask what was inside or why we couldn’t go in,” he said.

Ultimately, the crew had to install wires around the rooms, an unprecedented step in the field of steam fittings.

In addition, the crew once found confidential papers in a filing cabinet in the basement of the building.

The secret information was about what to do with machines in the event of a radiation attack.

Since its construction, the windowless building served as AT&T’s long-distance telephone exchange until 1999, when the company moved elsewhere.

Today, the windowless skyscraper is still sometimes used for its original purpose of telephone switching by some local telephone exchanges.

Other parts of the building are reportedly used as a high-security data center.

It is now better known as 33 Thomas Street, rather than the AT&T Building or the Long Lines Building.

Built under a cloak of secrecy, 33 Thomas Street was designed to withstand a nuclear explosion, according to an exclusive report on the building by The Intercept in 2016.

The 29 floors, including three basements, house enough supplies to feed 1,500 people for two weeks during a catastrophe, The Intercept reported.

However, the main goal was not to protect human life, but to secure critical telecommunications infrastructure.

Designed by John Carl Warnecke & Associates, the building’s vision was to create a communications fortress for the 20th century.

New York Telephone Company, a subsidiary of AT&T, led the project. The skyscraper was a hub for handling long-distance telephone calls and was touted as the largest of its kind in the world.

The Intercept’s investigation, along with information obtained from NSA whistleblower Edward Snowden, revealed that 33 Thomas Street is more than just a telecommunications center.

It appears to be a crucial National Security Agency (NSA) surveillance site, codenamed TITANPOINTE.

Although the documents do not explicitly name the building, architectural plans, public records and interviews with former AT&T employees provide compelling evidence.

Inside the building, a former AT&T engineer revealed the existence of a major international ‘gateway switch’, responsible for routing telephone calls between the United States and countries around the world.

Top secret NSA memos show that the agency tapped these calls from 33 Thomas Street.

This suggests that the skyscraper is a core location for a controversial NSA surveillance program that targets communications from the United Nations, the International Monetary Fund, the World Bank and at least 38 countries, including close US allies such as Germany, Japan and France.

While AT&T’s collaboration with the NSA on surveillance is well-known, Snowden’s documents shed new light on the role of specific facilities at the time.

They revealed how the NSA integrated its equipment into AT&T’s network in New York City, providing insight into the methods and technology used to collect communications data.

Dailymail.com contacted AT&T for comment.

Elizabeth Goitein, co-director of the Freedom and National Security Program at the Brennan Center for Justice, said: “This is yet more evidence that our communications service providers have, willingly or unwillingly, become an arm of the surveillance state.”

She emphasized the need for vigilance, as the effects of such surveillance could extend beyond non-Americans.

Every few years, images and videos of the creepy skyscraper recirculate on social media – in 2017, even Tom Hanks tweeted: ‘This is the scariest building I’ve ever seen! WTF is going on inside??’

Videos of the building were recently shared on Twitter and Reddit, and commenters began conspiring about what was inside, with one person writing, “Gives MI-6 vibes,” and another joking, “Lizard people don’t have windows necessary.’

Some social media users are leaning into the wild theories, while others aren’t so convinced.

One Redditor wrote: ‘Probably a data center and not inhabited by humans,’ while another added: ‘It’s a central telecom office, not a big mystery at all, most big cities have several. Because of the equipment, it is air-conditioned.”

Meanwhile, users on Twitter theorized: “So this is where all the vampires live now?” and, “Looks like something that should be in Dune.”

The vampire theory has proven popular, as users joked that they wouldn’t be able to work if sunlight came in through the windows.

Others are convinced that little green aliens and other aliens are being hidden from the world, behind the building’s creepy walls.

One user said, “This is where they’re keeping the aliens,” and another added, “100% Lizard HQ.”

Another guessed: “I think this is the headquarters of Men in Black,” while someone else asked: “Gotham city?”, joking that the skyscraper belongs in Batman.