This now-abandoned outcrop is an important Native American spiritual site, overtaken by European settlers and mining pollution.

A focal point of in Denver’s skyline for over a century, inspired by a Venetian basilica.

This unassuming passageway played a key role in one of the most important events in U.S. history.

Also known as the Founding Church of Scientology.

The innocent intentions of this monument are somewhat lost in the sculpture's muscled imagery.

This sidewalk tribute honors Colorado's great culinary creation.

The first memorial dedicated solely to the Black troops who fought for the Union.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

A hidden passageway now marks the site of an assassination attempt on Ronald Reagan that some say broke a 140-year-old curse.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

The huge collection of paintings of the American West is one of Denver's best-kept secrets.

This robust fence in front of a historic Georgetown home is likely made from hundreds of recycled Revolutionary War firearms.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

There’s a hidden military meme engraved on the World War II Memorial.

The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

A historic neighborhood church is reborn as a psychedelic arts collective.

This lovely picnic spot featuring thunderous jet landings is an aircraft spotter’s dream.

Rumor has it the hot dog stand was targeted by two Russian nuclear missiles.

This was once the home of Gahan's Saloon, Denver's most storied speakeasy.

The spot in the Mile-High City that's exactly 5,280 feet above sea level (at least for now).

The final resting place of an unidentified revolutionary soldier sits behind a Virginia church.

This poor little statue is the most vandalized memorial in Washington.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.