Also known as the Temple of Poseidon, this is one of the best-preserved Greek temples in the world.

Constructed during the 1960s, this bridge is still the highest in Italy.

Every day is like Christmas on this street where the traditional Neapolitan nativity scene comes to life.

Ancient snack bar of the Roman Empire re-opened.

A beautiful but toxic fountain of mercury.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

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

The only urban monument in the world designed by the great surrealist painter Salvador Dalí.

Commonly acknowledged as the only public monument to the Devil himself.

A lush indoor jungle fills this bustling Madrid transportation hub.

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

A whimsical brother of the nearby Fallen Angel statue takes the falling part quite literally.

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

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

"Portugal's Stonehenge" is made up of nut-like stones aligned with the heavens.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

The medieval castle built as headquarters for the Pope's secretive Knights Templar.

Ancient catacombs form the foundation for this Rococo orgy of a church.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

A statue honors the children who fought Nazis in Poland.

A striking public sculpture representing the period of martial law in Communist Poland.

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

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

An underground city of salt.