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

A stunning 18th-century site where pilgrims ascend by a series of punishing stairs only to return via funicular.

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

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

A unique seaside cave where Aleister Crowley faked his own death.

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

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

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

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

A desert ghost town—occupied for only 12 years—was once home to more than 500 silver mines.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

A hand-built folk art installation covered with messages of God's love.

The house that took a plunge into the facade of a museum.

The site of Austria's biggest concentration camp now honors its victims.

In the fictional world of Kcymaerxthaere, standing at this site just outside Vienna, Austria, the sky would have been found beneath your feet.

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

The solemn exterior conceals an opulent interior of this 17th century church.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

The shell of a medieval fortress offers commanding views of the area it once protected.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

Baroque celebration of the end of the Great Plague of Vienna.

Op-art architecture designed for happiness.

Legends surround an ancient tree trunk riddled with nails for good luck.