A mysterious monument meant to be a guide into "an Age of Reason" was destroyed after an apparent bombing.

This iron and wood Civil War city-ship was the first vessel to be sunk by an electrically detonated torpedo.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

The U.S. Supreme Court's secret Cold War relocation facility in the mountains of North Carolina.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

The final resting place of the Seminole Indian chief who fought against government occupation in Florida.

This recently rediscovered Civil War-era submarine was the first to ever sink an enemy ship.

A quirky Poe-themed joint on an island keen to celebrate its overlooked connection to the famous writer.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

An extensive, if one-sided, history of U.S. law enforcement's war on drugs.

Hear the quietest sound from across the dome.

A "hospital" where people went to be quarantined, die, and be buried in the yard.

A quintet of history museums make this Virginia graveyard as much a resting place for funereal history as it is for people.

This taxidermy horse was a Civil War hero.

America's Most Wanted's set resides in this tribute to the history of crime and punishment.

This bleach-white graveyard overlooking the ocean is accessed through a tunnel.

Legend tells how a Spanish soldier disappeared from this isolated sentry box without a trace.

This chapel on a cliff is renowned for its healing powers and was founded on the site of a supposed divine intervention.

This limestone cave offers an incredible view of the Río Grande de Arecibo valley.

The world's second largest single-dish radio telescope, once used to contact E.T.

The fantastic charm of England's oldest botanical garden has made it a place of writerly inspiration for centuries.

Used as an example in one of the first dictionary entries for "museum" in 1706.

A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.