Built by the patriotic residents of Boonsboro in a single day.

Historic barracks utilized during both the Revolutionary War and the Civil War.

This hidden treasure provides a charming access point along the south side of Baker Park.

A Civil War Museum with some notable medical antiques.

According to local history, this cast-iron canine was nearly melted down for bullets during the Civil War.

Rumors persist that a bottle of whiskey is sealed within this Demijohn-shaped adornment.

A labor of love built by local hang-gliding enthusiasts, this ideal launch spot was outlawed by the authorities and has since been largely abandoned.

The oldest liquor store in the country is a model of resilience and mischief.

Continuing the tradition of the dime museum in style.

A charming "tea atelier" hidden away in Greenpoint, Brooklyn.

The story behind the mysterious symbol painted in front of the historic university's famous Rotunda.

A swimming hole in the historic industrial quarry that supplied the marble for the Baltimore Washington Monument.

The Cold War-era "underground Pentagon" is a sprawling subterranean hideaway for the Defense Department.

The oldest farmer's market in America is so ancient it was approved by the King of England.

Bizarre Cavern.

An almost life-sized elephant named Ms. Ellie greets visitors at this jumbo-themed museum.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

The house where John Wilkes Booth conspired with his co-conspirators.

A small triangle of DC grass is the final resting place of one of Sonny and Cher's songs.

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

The oldest Italian café in Boston, this spot also serves as a veritable museum of vintage coffee ephemera.

An enormous, inside-out glass globe built in 1935.

The infamous Boston Mob ran rackets from an office here in the 1970s.