A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

Blighted Irish field and the ruins of a 19th-century cottage on the edge of urban Manhattan.

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

This castle-like building in Manhattan helped destigmatize cancer in the 19th century.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

The "Seinfeld" diner.

Visit the monolithic tomb of America's most famous general.

A curious fountain that has no water and includes Satan, a crab, and 9 giraffes.

An effigy of a trapped paratrooper dangles from a Normandy church to commemorate one remarkable D-Day event.

A daring D-Day assault by U.S. Army Rangers is commemorated atop the high cliffs of this strategic point.

A memorial to the nearly 10,000 American soldiers laid to rest on the beaches of Normandy during WWII.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.