An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

This bridge over D.C.'s Rock Creek Park is sometimes called the "Buffalo Bridge" because of its four buffalo sculptures, which were cast from a single piece of bronze.

Behind an abandoned storefront is an example of pioneering 1930s gas station architecture.

The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

This geometric feat is a testament to the Incas' mesmerizing architectural abilities.

Built on the remains of one the Incas’ most important gathering spots, this square keeps the spirit of a fallen empire alive.

Situated on a sacred Inca site, this 16th-century cathedral took nearly 100 years to build.

Picturesque basketball courts sheltered by historical defensive walls and with an enviable sea view.

The largest burial mound in the United States holds the remains of prehistoric West Virginians.

Time travel with sweets across history at this research-based candy store.

Sky ships, planes, and portraits left as unique tokens of hope and thankfulness.

A wunderkammer of gold and silver reliquaries and ancient saintly bones.

A full figure 4th century incorruptible saint lies in a glass coffin in Croatia.

Gargoyle head that brings good luck.

An ancient knight and a symbol of the city's freedom.

The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

An ancient site that has revealed incredible artifacts including portions of the Themistoclean Wall.

A tiny Greek Orthodox church from the Ottoman era hides on a busy city street.

The legacy of a Moroccan Jewish community is remembered at this little mouldering cemetery.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

When World War II came to Canada, Fort Péninsule was part of the first line of defense for Allied shipping convoys.

An abandoned underground bunker not far from downtown New Orleans.

A whimsical bridge adorned with decorative dragons.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.