Mexico's astounding mummy museum with "the world's smallest mummy."

The stoutest tree in the world.

The only castle in North America to ever house European sovereigns.

Part bookstore, part café, and part forest.

Go inside to really appreciate this 500-year-old technological masterpiece.

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

The world's largest wooden structure.

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

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

This bridge was constructed from the rubble of the infamous Bastille.

What's left of the ruins of the 1893 Columbian Exhibition, or World's Fair, also known as the White City.

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

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

An awe-inspiring mosque in Morocco with one of the tallest minarets in the world.

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

The earliest known map to show America, discovered by accident at a Paris bookshop.

An ancient Egyptian temple in the middle of Madrid, Spain.

North America's largest accredited model railroad museum.

Breathtaking and huge 430 year old maps of Italy.

California's oldest wind harp represents a historic piece of America's Danish history.

A fortified city, home to a remaining population of five families