A striking memorial to the 21 lives lost in an explosion at the Washington Arsenal

The privately owned cemetery that holds room for Washington's finest when they step down from life.

One of the three perfect vellum copies of this historic book known to exist is on display in a specially-designed case.

Engraved in stone here are the signatures of everyone who signed the Declaration of Independence.

A museum dedicated to the history & joys of the trail & your best chance to see hikers throwing up ice cream.

This museum celebrates a legendary railroad photographer whose personal life was as dramatic as his photos.

The Home and murder site of the witch of Rehmeyers Hollow.

Under a playground is a little-known sealed train tunnel that likely contains the bodies of workers trapped by cave-ins.

A small Richmond island dotted with the remnants of hundreds of years of history.

Alexander Hamilton’s creation caused quite a bit of controversy.

At the birthplace of American railroading, a world-class collection of historic trains.

A perfect circle of 24 mysterious holes dates back to prehistoric times.

The iconic Manhattan corner that was once the site of the Beastie Boys' fake clothing store.

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

Outsider art meets paleontology at this roadside reptile repository.

Go surfing on this urban wave, "hacked" by local surfers.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

The scars of World War II are preserved on its walls.

These 12th-century catacombs carved into a mountainside were a place of mysticism and Christian hermitages.

A small square plaque marks a failed assassination attempt that could have changed history.

Golden cobblestones remember a time when this small alley was used to avoid having to give a Nazi salute.

The patron saint of spinsters grasps a container of dried blood.

The prototype for all Nazi concentration camps.

A fearsome dragon clings to a corner of Munich's city hall.