America is home to a remarkable network of underground cities and hidden complexes that many people have never heard of. Some of these subterranean places are steeped in history, while others serve as top-secret government facilities designed for safety during catastrophic events. From tunnels beneath bustling metropolises to vast underground business hubs, these shadowy spaces reveal a fascinating layer of American life that lies beneath the surface. Here are 30 intriguing underground cities and locations across the United States that you never knew existed.

1. Raven Rock – A Government Fortress Beneath the Mountain

Raven Rock is a secret underground city carved deep within a mountain, designed to serve as a secure emergency shelter for U.S. government officials in the event of a nuclear war. Located 768 feet below ground, the base boasts massive blast-resistant doors and multiple buildings spread over 15 floors. Complete with facilities such as a barbershop, medical center, and water generators, Raven Rock is a self-sustained underground city built during the Cold War era to survive even a direct nuclear attack.

2. Underground Atlanta – A Historic Commercial Hub

Beneath downtown Atlanta lies Underground Atlanta, a network of streets and buildings initially built around the railroad in the 1800s. In the 1920s, the city raised its streets, creating an entirely new underground level bustling with shops and businesses. Forgotten for decades, Underground Atlanta was revitalized in the 1960s as a lively entertainment district featuring music venues and bars. Today, it combines its rich history with modern redevelopment efforts.

3. New York City’s Hidden Subterranean World

New York City’s underground labyrinth extends far beyond its famous subway system. The city hides secret tunnels under areas like Little Italy and the Meatpacking District, as well as abandoned stations such as the ornate City Hall station, which closed in 1945. The underground includes historic mail tunnels from the late 19th century, railroad tunnels, and even ancient artifacts like a 1600s ship discovered just 15 feet below the streets.

4. Permafrost Tunnel Research Facility – Alaska’s Frozen Time Capsule

The Permafrost Tunnel in Alaska, dug between 1963 and 1969, is a scientific marvel used to study frozen ground over 40,000 years old. Inside, layers of permafrost reveal ancient ice, plants, and animal bones, providing crucial insights into Earth’s climatic past and the challenges of building infrastructure in frozen environments.

5. Mini Manhattan – A Nuclear-Resistant Underground City That Never Was

In 1969, architect Jay Suy proposed “Mini Manhattan,” an ambitious plan for an enormous underground city designed to shelter up to one million people during a nuclear attack. The concept featured underground skyscrapers, parks, theaters, and all the essentials for long-term survival. Although never realized, this visionary project inspired smaller developments like the Atom habitat in Texas.

6. SubTropolis – The World’s Largest Underground Business Complex

Kansas City’s SubTropolis is an expansive limestone-carved complex spanning 55 million square feet. It houses offices, storage facilities, and factories, benefiting from naturally cool temperatures year-round. Over 1,600 people work in SubTropolis daily, making it a unique bustling underground economic hub.

7. Seattle Underground – The City Rebuilt Above Its Ruins

After a devastating fire in 1889 destroyed downtown Seattle, the city was rebuilt with streets raised above the original ground level. This left the old street-level buildings and pathways abandoned below, forming the Seattle Underground. Closed in 1907 due to illegal activities, these tunnels reopened in the 1950s as a tourist attraction, offering visitors a glimpse into the city’s fiery past.

8. PATH – Toronto’s Extensive Underground Walkway

Connecting over 70 buildings and extending more than 30 kilometers, Toronto’s PATH system is a vast underground network offering convenient, weather-proof pedestrian routes. Housing thousands of shops and services, it’s a vibrant subterranean city beneath Canada’s largest city, frequently used by over 200,000 people every day.

9. The Greenbrier Bunker – Congress’ Secret Cold War Shelter

Hidden beneath the luxury Greenbrier Hotel in West Virginia lies a massive Cold War era bunker designed to house the entire U.S. Congress in case of nuclear war. Boasting blast doors and decontamination rooms, the bunker remained top secret until exposed in 1992. Today, guests can tour this extraordinary facility.

10. Nashville’s Underground Tunnels – Civil War and Prohibition Secrets

Beneath Nashville’s streets are hidden tunnels dating back to the Civil War era, historically used for smuggling and transporting soldiers and goods. Over time, other tunnels were built for utilities like steam and cold water delivery. Some are rumored to have been escape routes during Prohibition, adding an air of mystery to these secret passages.

11. Bluegrass Underground – A Concert Venue Below Tennessee’s Surface

Nestled deep within a cave 333 feet underground in Tennessee, Bluegrass Underground is a unique music venue known for its stunning acoustics and unusual atmosphere. Hosting various live performances, it attracts music lovers who want to experience concerts in an unforgettable subterranean setting.

12. Indianapolis’ Hidden Catacombs

The city market in Indianapolis sits atop a network of underground catacombs and tunnels. While many visitors enjoy the surface-level market every day, few realize the extent of these historic underground passageways, which are steeped in the city’s commercial and social history.

These are just a handful of the many amazing underground cities and secret spaces scattered across America. From government bunkers and ancient tunnels to commercial complexes and cultural venues, the hidden worlds below offer fascinating stories, incredible engineering, and a glimpse at how life continues beneath our feet. Exploring these subterranean places reveals that the true depth of American ingenuity and history often lies underground.