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

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

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

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

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

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

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

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

Elaborate tile work in this railway station tells the story of Portugal.

The stunning interior of this Gothic church is covered in ornate gold details.

Europe's oldest still-operational tea farm also boasts a spectacular view.

Legend has it the lovelorn tears of a princess and a shepherd boy formed the blue and green twin lakes in the Azores archipelago.

One of few vertical lava tubes in the world accessible by foot.

A stunning Catholic cathedral built by a curve-loving communist in Brazil’s newly created capital.

Henry Ford's failed rubber plantation in the middle of the Amazon rain forest.

A faux desert landscape in the middle of the jungle that sprouts oases during the rainy season.

A Tudor-style castle in Brazil holds one of the world's largest armory collections.

The massive gardens and office of a Brazilian sculptor.

Abandoned city hidden from the world by tropical forest and isolation on the coast of Kenya.

This colonial fort is an intriguing example of Renaissance military architecture.

Stunning ruins of what was once the center of one of the greatest empires in East Africa.

Structure built from the skulls of vanquished foes.

A Red Cross memorial museum at the site of the Niš concentration camp that operated for four eventful years during World War II.

This museum preserves the hand-dug tunnel that kept Sarajevo afloat during the Serbian siege.