Eat the ultimate iteration of Portugal's most beloved pastry.

Entire apothecaries are on display at this Lisbon museum, which explores the history of medicine.

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.

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

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

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

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

The world's largest wooden structure.

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

Once the grandest synagogue in medieval Spain, it now stands as a memorial of the 15th-century Jewish exile.

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

This fascinating and poignant museum chronicles every imaginable aspect of Spanish colonialism in the Americas.

A lush indoor jungle fills this bustling Madrid transportation hub.

It was once the base for a series of domestic terror attacks.

The story behind this beloved toy—named for Theodore Roosevelt and owned by his grandson—is more complicated than you might guess.

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

The 28,000-year-old specimen is remarkably intact.

The preamble to the U.S. Constitution written entirely from vanity license plates hangs in the Smithsonian museum.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

Largest Roman Catholic church in North America.