A pair of giant roadside arrows are all that remains of a former Route 66 trading post.

An eatery for UFO seekers on the Extraterrestrial Highway.

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

Dramatic river bend surrounds a natural red-rocked pedestal.

Yo, Adrian!

This elaborate towering structure was once famed for its revolutionary height.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

Erected in 1697 this Philadelphia bridge is the oldest surviving roadway bridge and perhaps the oldest stone bridge in the United States.

American revolutionaries and British soldiers alike are buried here in the fourth-ever cemetery in Boston.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

The site where Charles Dickens gave his first public reading of "A Christmas Carol" in the US.

The Boston square dedicated to the dark poet who was born nearby.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

The tomb of Increase Mather and his son Cotton, influential colonial ministers obsessed with the occult.

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

One of the indelible moments of the American Revolution took place at this location.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

This landmark cemetery in Boston was created more than 300 years ago.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

This Delaware River bridge is emblazoned with a catty slogan from a more prosperous time.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.