This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

Spain's largest bullring offers a unique glimpse at architecture and history.

The fragmented remains of a massive public bath connected to the city's water supply.

Originally used to sell brandy, the bull-shaped billboard became an iconic symbol of Spain.

Spanish architects used seized Muslim gravestones to rebuild parts of the fortress.

A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

The final resting place of the great navigator, or maybe his brother.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

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

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

One man's remarkable private collection of art from around the world.

An exquisite collection of fairytale conveyances that puts most car museums to shame.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

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

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."

Home to three historic ships from the age of Vikings.

Seventy-five miles of limestone caves host more than a million bottles of wine beneath a sleepy Moldovan town.

A forgotten remnant of the Soviet Union, Transnistria is an unrecognized country hidden behind a heavily militarized border between Moldova and Ukraine.

The reconstruction of this prominent building fulfilled a long-written command.