Last week, Untapped Cities reader @nationsofnations tweeted at us, asking us if we had a story about the “replica bridge on top of buildings in brooklyn.”

A photo she took from a car gave us the clue we needed: rather than a replica bridge, they’re the WWII radio towers once used by the Navy, specifically the Third Naval District US Naval Communication Center Headquarters. They sit atop the 1940s-era building, 25 Washington Avenue, in the Brooklyn Navy Yard, and part of Steiner Studios.

In this forum, Navy seamen who worked at the station mention using it to communicate with the Bermuda station, with ships coming in and out of the New York City harbor, and one guys mentions tracking Sputnik (which another refutes). The New York Post writes, “The spidery structures uncannily conjure the era of warships in the roiling Atlantic with which they communicated.”

Andrew Gustafson, vice president of Turnstile Tours, a company that gives tours of the Navy Yard, confirms that there isn’t too much well-documented information about the towers themselves. He says, “You may find reference to it being ‘strong enough to reach Puerto Rico, which was in the Third Naval District,’ which is not correct. That is not a comment on the power of the antenna – again, I have no idea – but on the fact that Puerto Rico was in the Third Naval District only from 1903 to 1919, long before this building existed.

Brooklyn Navy Yard WWII Radio Towers-Sketch-PlanDennis Riley, archivist for the Brooklyn Navy Yard shared with us architectural drawings related to the towers

He continues, “The transmitter sits on top of Building 1 or Building 291, which was built in 1942 as the Material Sciences Laboratory. This building housed much of the primary research operations of the Yard, including testing the resilience and properties of materials and equipment used by the navy, as well as developing radio, radar, sonar, and other electronics and navigation equipment. Much of navigation system for the Polaris nuclear submarines was developed in this building.”

Studios Chairman Doug Steiner also had the radio towers lit up too, “in an understated, blue-and-white way. They’re not going to blink,” reports the Post. Today, the building holds not only Steiner Studios but also Carnegie Mellon’s Integrative Media Program and Brooklyn College Graduate School of Cinema.

See more photos inside the Brooklyn Navy Yard and the beautiful crumbling mansions of Admiral Row