It houses the remains of a 17th-century version of the Titanic.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

This series of Baroque passageways in Vienna's cultural center mix old architecture with modern art.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

Two stone columns flank the grand Venice square, but there were supposed to be three.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

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

A towering work of stone and philosophy that was constructed using ancient Hindu science.

Eternal flame said to be a Hindu Goddesses fiery tounge.

An ancient iron pillar in Delhi that seems to be rustproof.

A blooming house of worship for the masses.

A complex of six forts embedded in the Rajasthan hills.

A centuries-old fortress city lies in ruin.

Modest by day, illuminated majestically at sunset.

Temples adorned with intricate, erotic sculptures make up one of the "seven wonders" of India.

The world's second-largest sundial, made entirely out of stone.

The remains of what was, not so long ago, the world's largest city.

More than half of this Indian palace is drowned but it looks all the more spectacular for it.