A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

This labyrinthine resting place of Black American leaders has been reclaimed by nature.

The first and only carousel with a lineup entirely of insects.

The famed amusement district marks the beginning of summer with a wild procession of nautical creatures.

This outdoor gallery of graffiti-covered walls pays homage to the past, present, and possible future of street art.

Sniff the Titan Arum's rotting flesh.

The one-time epicenter of American songwriting is now a little remembered Manhattan commercial block.

A collection of fanzines, recordings, and documents detailing the rise and influence of the feminist punk movement.

Commemorating the spot where the famous scientist fed his pigeons.

The rough and tumble president's childhood home displays the shirt he was once shot in and the speech that saved him.

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

The world’s oldest and biggest bookstore stocking only mystery, crime fiction, espionage, and thrillers.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

New York's oldest magic store.

Try not to get slimed in Tribeca.

Elevated freight railway turned wildly successful urban park.

Home to a vast and influential collection of Shakespeareana.

This lovely pocket park is one of the most under appreciated in D.C.

People escaping slavery may have hidden inside a corpse vault.

The walls of the iconic dome are hollow and have a secret stairway.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.