Conspiracy theories were rampant about the building after the Apollo 13 star posted a tweet to his more than 13 million followers asking what was up with it.
“This is the scariest building I’ve ever seen! What goes on inside??” he tweeted last week.
This is the scariest building I've ever seen! WTF goes on inside?? Hanx. pic.twitter.com/nXeUI64rXm— Tom Hanks (@tomhanks) June 2, 2017
His tweet sent social media into a frenzy of speculation, with people calling it everything from the Men in Black headquarters to the National Covfefe Center.
“I heard all kinds of secret stuff that happens inside there,” according to another Twitter user willing to chime in.
Still another said, "If I was an evil genius I’d definitely have my headquarters there.”
The windowless brick building only has massive air vents on its top floors and midsection.
The building is owned by AT&T and it doesn't have any windows because it may be the only New York City skyscraper designed to withstand a nuclear blast.
The skyscraper is located at 33 Thomas Street in lower Manhattan.
According to a 2016 documentary Project X – Field of Vision, the building houses AT&T's telecommunications infrastructure and also serves as a listening post for the National Security Agency.
“Just look at the building — it has got no windows — it looks like something from a space movie,” Henrik Moltke, who co-directed the documentary, told Inside Edition. “The building is very sensitive to the sun and temperature. That is why you have these big vents that you can regulate. Basically, it is like a big air conditioner.”
The film is narrated by Mr. Robot star Rami Malek and the building is featured in his hit show.
While the building may look intimidating, it could be the safest place to be in in the event of a nuclear attack. There's reportedly enough food, water and generator fuel to sustain 1,500 people for two weeks.
When Inside Edition tried to get more answers, security in the building told us the place is off limits to cameras.
For more information about the building and to read Moltke's work about it, click here.