The oldest continuously operating fish market in the United States.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

A computer bug so primitive it was an actual insect.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

A wondrous old library overlooking the nation's capital.

They sort through millions of dollars worth of diplomatic gifts on behalf of the government.

The national park was once a plantation estate.

An unknown number of cholera victims are buried in two nondescript graves.

The large rock formation where the Shawnee prophet Tenskwatawa stood and encouraged his warriors during the Battle of Tippecanoe.

This elaborate estate contains a stunning marble aviary, a sunken conservatory, and a magnificent music room with a two-story pipe organ.

Tiny horses tethered to antique rings are scattered around the city.

Portlandia is the second-largest copper repoussé statue in the United States.

Inside a humble hangar is some of the best roller derby the world has to offer.

This sandstone mansion was the home of two of Oregon's most important pioneers.

A restaurant on Staten Island showcases a different grandmother’s cooking every night.

One of Chicago's last seafood smokehouses perfects a dying breed of fishcraft.

A gorgeous gilded tower houses what may be the world's largest collection of gin.

Eat a Nobel banquet from any year in the basement of Stockholm's City Hall.

This red London phone booth once stood in front of Buckingham Palace and was used by the queen.

Walk inside a half mile long crevice right outside the town of Garmisch Partenkirchen.

Shimmering sea-colored mosaics and Jesus statues cover this opulent building.

When a medieval fire claimed the original St. Stephen’s Cathedral, it sparked a pattern of unquenchable organ building.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.