A 16th-century fountain marks the site of a lost medieval cemetery once filled with mass graves.

Jesus' footprints and the first catacombs in the world.

2300-year-old Roman road connecting the empire.

Rome’s legendary peephole vista is also a former Crusader stronghold.

Historic medieval fortified city in southwest France.

This enormous "cloth of the conquest" depicts the Norman invasion of England in mind-blowing detail.

Explore this medieval cathedral by trying to spot all the malevolent monsters hiding in its beautifully colored windows.

This demon atop the Notre-Dame de Paris looks utterly bored.

Featuring the the longest lift span of any vertical-lift bridge in the world.

Once in a state of dilapidation, this candy-inspired fortress is now being revived.

Tucked behind New Jersey's abandoned Gingerbread Castle lie the eerie ruins of a once-flourishing paper mill.

An image of the legendary saint stands in the shadow of a cathedral she liberated.

The walls and streets of the ancient city are peppered with penises.

Quito's historic, main square dates back to the 16th century.

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

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

Pulled from the rubble of one of the worst modern tragedies, a steel crossbeam became a symbol of hope for New Yorkers.

Touching this 18th-century Scottish philosopher’s toe allegedly conjures good fortune.

This beautiful deer park was built so King Charles I and his court could go hunting while escaping a deadly plague outbreak.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

A statue of the legendary Celtic warrior queen who fought the Roman invaders stands in one of the cities she once destroyed.

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

Coast along one of Japan’s mountain railways for coveted views of magnificent hydrangeas.