Standing at 33 Thomas Street in the Civic Center neighborhood of New York City is a 550-foot tall monolithic, granite-clad, concrete building. Even in a city like New York, where tall buildings are typical, people passing by would look up to gaze at this intimidating structure —their attention drawn not by the building’s height but by its fortress-like appearance. Aside from a couple of ventilation openings on the sides, the building’s bare concrete slab façade is without a single window.

The Long Lines Building is owned by the multinational telecom company AT&T, and is indeed an impenetrable fortress. When it was built in 1974, AT&T asked architect John Carl Warnecke to design a structure that could withstand a nuclear blast and protect its occupants from fallout for up to two weeks after the attack. Such concerns were not uncommon at that time, and AT&T wanted to be sure that their expensive equipment stayed undamaged.

The building was originally built to house AT&T’s solid-state switches and other equipment for the company’s long distance telephone lines, hence the name Long Lines Building. These switches required a high level of security and space, so the floors of the building are taller than average. Each floor is 18 feet high, so even though the building is as high as a 40 story tower, it has only 29 floors. The floors are also designed to bear an extremely large amount of weight.

The building continued to function as AT&T’s long distance telephone exchange until 1999. After that AT&T vacated the building and moved a few blocks away. The building is still used for telephone switching by some local exchange carriers, but some of the space is also used as a high security datacenter.

Since AT&T moved out, the building has been referred to by its street address 33 Thomas St., like many major New York City commercial buildings.

No outside view.