Beneath the streets of Washington D.C. lies a fascinating network of tunnels that remain largely unknown to the public. These passageways, ranging from public pedestrian walkways to government-only corridors, reveal a hidden side of the nation’s capital. Did you know the Capitol is connected to other federal buildings by tunnels originally designed to shield legislators from harsh weather? Or that a secret conveyor belt once transported books from the Library of Congress directly to the Capitol?

The tunnels beneath Capitol Hill go beyond practicality—they’ve been a part of critical moments in U.S. history. During the Cold War, they were reinforced as fallout shelters, and more recently, they provided secure escape routes during the chaos of January 6, 2021. Even the FBI attempted to use tunnels for spying under the Soviet Embassy during Operation MONOPOLY, though the plan was riddled with technical failures.

These passageways also hold quirks and hidden treasures, like the Cannon Tunnel, where student art decorates the walls alongside post offices, cafeterias, and even shoe repair shops. In some tunnels, abandoned projects like unfinished subways serve as reminders of forgotten ambitions. And while the public sees only a fraction of these tunnels, restricted corridors link the Capitol, Supreme Court, Library of Congress, and even secret White House bunkers.

Explore the stories, mysteries, and surprises of this underground world. From secret passageways used by presidents to logistics innovations like driverless Senate subways, these tunnels are far more than simple pathways—they’re a glimpse into the hidden history of Washington D.C.