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

The remnants of a creative early method of wildfire prevention.

The blinking light atop the iconic landmark has been sending secret messages for decades.

A historic blockhouse and trading post give a glimpse into the early colonial history of South Carolina.

The building was originally a gas station built to resemble a Japanese tea house.

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

A wonderful display of arts and crafts handmade by local artisans in the Southern Appalachians.

One of two lighted lanterns hung in the church belfry on the eve of the Revolutionary War to warn that the British were on their way.

The wooden airship was the largest flying boat ever built.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

An unexpected Easter egg lurks in the background of a cherub wall relief at the Breakers mansion.

Two small markers remember the Alamo's feline protectors.

The unique collection includes bronze cast handprints of some of America's most famous astronauts.

Originally used to sell brandy, the bull-shaped billboard became an iconic symbol of Spain.

A collection of outdoor art by renowned muralist Robert Dafford depicts the history of a flooded city.

Where school buses go to die and be reborn as whimsical works of art.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

There’s a hidden military meme engraved on the World War II Memorial.

Carved faces add a touch of magic to this island's impressive oak trees.

A rainbow-colored house promotes LGBTQ rights across the street from the Westboro Baptist Church.

Chicago's Navy Pier on Lake Michigan was a training hub for aircraft carrier pilots during WWII.

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

This recently restored timepiece has stood all around Kansas City.

St. Augustine's record-setting narrow street was designed to protect against pirates.