Man explains the exact purpose of the mysterious windowless structures across the United States

Editor's note: This article was originally published on March 22, 2023. It has since been updated.

Numerous windowless structures situated throughout the United States have aroused the interest of several people. Not many people know about their origin or purpose. Fortunately, an individual took it upon himself to clarify the purpose of these atypical constructions. Responding to a video clip from a curious individual about the presence of such buildings, Eric Guidry, who is known as @e.guidry on the video-sharing platform, remarked: "So that building in New York, this windowless building in San Francisco, this one in Chicago, this one in Austin and hundreds more buildings placed conspicuously across the country, in very populous locations."

It's not surprising that people are interested in these structures, as even Hollywood celebrities like Tom Hanks have pondered their purpose. In 2017, the "Forrest Gump" star tweeted a picture of 33 Thomas Street in New York, stating: "This is the scariest building I've ever seen! WTF goes on inside?"

As it happens, all of these buildings are components of AT&T's long lines network. Guidry explained: "Before we had digital telephony, the lines on your phones physically connected to the person on the other end's phone. That meant we need these massive switching hubs. Most of those buildings I showed were built in the '70s [or earlier]."

"That means they didn't require actual operators. And because this machinery didn't particularly care if there was light or not, they just decided, why add windows?" Guidry provided additional details about the AT&T building in New York that was highlighted in the original TikTok video, stating: "That building is 33 Thomas Street, which is known to be one of the most secure towers in the world. It has enough gas, water and electricity to be able to continue running independently for up to two weeks and is supposed to be able to actually withstand a nuclear blast... within reason."

"Although most of the equipment has been digitalized and you don't need it for phones, it's still critical for network and internet infrastructure," he added. "In fact, if you're watching this in the US, this video probably went through one of those buildings." 

According to Livabl, architect John Carl Warnecke designed and oversaw the construction of 33 Thomas Street in 1974, with the building's resilience in mind. It was engineered to withstand the impact of a nuclear blast for a period of up to two weeks, making it one of the most fortified structures in the United States. The building consists of 18-foot stories, each capable of supporting a weight of 200 to 300 pounds per square foot.

For over two decades, from its establishment until 1999, the building functioned as a massive telephone switchboard for AT&T Long Lines, which provided long-distance communication services. During its peak, 33 Thomas Street was responsible for routing approximately 175 million phone calls per day. However, AT&T eventually relocated its operations to its current headquarters at 32 Avenue of the Americas, leaving the building vacant. Nevertheless, the AT&T logo is still visible on the building's entrance.