This 2,000-year-old Doric bridge is still open to pedestrian traffic to this day.

Malta’s largest cemetery is a Victorian-era architectural masterpiece.

A centuries-old forgotten underworld lies beneath Malta.

The celebrated eyesore created by starry-eyed sweethearts.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

A Victorian park cemetery, standing on the site of what was once the Great North Wood.

The sixth of London's "Magnificent Seven" cemeteries, and a source of unlikely inspiration to Beatrix Potter.

A house of bones — but nobody is quite sure to whom they belong.

Winding paths and ramshackle mausoleums in the oldest "park cemetery" in London.

A vast overgrown cemetery, once known as one of London's "Magnificent Seven."

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

One of the most poignant ruins of the Chornobyl nuclear disaster, the local football team's stadium has been quickly reclaimed by nature.

This attraction was abandoned after the Chornobyl disaster.

The decaying ruins of Wales' first asylum for the mentally ill.

The final resting place of soldiers' loyal canine companions.

This enormous abandoned prison was once dubbed the "Bastille of Romania."

This shuttered power plant is now Turkey's first industrial archaeology museum.

The most impressive of Basel's three remaining city gates.

An old spa town in the mountains of Romania where, according to legend, the great hero Hercules once bathed.

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

An underground city of salt.

This virtually windowless mass of smooth concrete is the only Catholic church in the city.

These purpose-built WWII air raid shelters, which run half a kilometer under the town of Mellieħa, are among the longest in Malta.

The design of this beautifully crafted building was inspired by Norwegian glaciers.