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Growing up in Washington, you learn the city’s secrets on the playground. When Billy says his dad “works for the State Department” but can’t be more specific, knowing looks are exchanged and “CIA” is whispered.

Of course, when you’re older and your friends work for the State Department, and you wouldn’t want them to bore you with the details if they could, Billy’s dad, who was probably just some GS-12 cog anyway, starts to lose that Bondian appeal.

And so, while Washington is undoubtably full of dummy corporations hiding NSA operations, counterintelligence cells masquerading as import/export business, and some of the people rounding Dupont Circle may be doing that Eiger Sanction thing, residents take for granted, and largely ignore, the obvious covert machinations of our great federal government.

Can vestiges of such operations be found at Fort Reno? The old fort is home to many odds and ends of the federal and municipal governments, including an Army Corps of Engineers/Washington Aqueduct pumping station inside the fattest of the grounds’ three towers and two underground holding tanks for city water. The Secret Service’s K9 division bunks in and around the smaller tower topped with the witch’s hat. Despite the canine presence, the fort is also home to a bijillion black-and-white stray cats, all descendants, I’m told, of a couple of felines rescued by one of the Secret Service officers. The Department of Public Works stores salt, sand, and other snow removal equipment at the fort.

And then there is the mystery tower. It’s just a large cylinder, with a few nondescript antennae jutting out from its roof. The tower stands next to a building that resembles a large, rust-colored tool shed. Both are protected by a high chain-link fence topped with barbed wire. Posted on the fence at various points are signs informing the curious that this is Federal Aviation Administration (FAA) property and that any interference could result in the destruction of aircraft and loss of life.

Fine. As evidenced by the multiple TV and radio broadcast antennae nearby, the fort, found between Tenleytown and Friendship Heights, is located on one of the highest points in the city, and the FAA might have some reason to broadcast from there. Except that you can discern an underground installation beneath the structures, and old hands in the neighborhood remember that a few years ago the cover story for the buildings was that they were part of the waterworks. People who have asked questions about the installation were brushed or scared off.

But don’t let that deter you. The federal government—even the branches that build bunkers, string up barbed wire, and invent cover stories—is our friend, and not to be feared.

A Washington City Paper T-shirt will be awarded to the brave citizen who uncovers the true purpose of the Fort Reno tower. Inspired answers will appear in next week’s edition if they reach us by Tuesday. Submit your description, or suggest topics for this column, by writing to: Mysteries, Washington City Paper, 2390 Champlain St. NW, Washington, DC 20009. Our fax number is (202) 462-8323, or e-mail us at Mysterieswashcp.com. No phone calls, please.