This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Founded as a refugee camp, now a popular tourist spot.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

One of Europe's largest supercomputers is housed inside of a disused chapel.

A beautiful but toxic fountain of mercury.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

Turntable anonymously received orphans, alms, and groceries.

Science fiction's grandfather has a fittingly marvelous tomb.

The celebrated eyesore created by starry-eyed sweethearts.

Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

This bridge was constructed from the rubble of the infamous Bastille.

Museum on French naval history, with magnificent figureheads, a historic diving suit, and a boat used by Napoleon.

Huge winged monument in the United Kingdom.

A book bound in the skin of an infamous criminal, along with countless other specimens.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

360° views of the city plus five floors of optical illusions and hands-on science.