This castle has links to Portugal’s founding and struggles for independence.

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

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

The elegant manor house where Kaiser Wilhelm II lived in exile after World War I.

Lombardy poplars planted to imitate the size and shape of the Cathedral of Notre-Dame de Reims.

The unique collection often goes unnoticed by visitors focused only on the archaeological objects.

Once home to an aristocratic family and a workers' organization, this intricately tiled building now houses a chain restaurant.

Many people don't realize there’s a lot going on in—and below—the world’s tallest triumphal arch.

These haunting ruins of a 700-year-old Prehispanic city have witnessed centuries of wars and massacres.

Every equinox this Maya pyramid puts on a spooky ancient light show.

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

Frida Kahlo's childhood home, now a museum of her life and works.

Hidden for more than a century, the grave of the Conquistador remains forgotten behind these church walls.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

These sacred Mesoamerican ruins feature peculiar petroglyphs hidden in the stones.

An elaborate Mayan city shrouded in alien conspiracy revealed the tomb of Pacal the Great.

This almost-forgotten underground dungeon housed several convicts over the years, including Caravaggio.

The floor of this spectacular Baroque sanctuary is covered in memento mori.

Built to repay the sins of the father, this church is home to one of the most valuable works of Western art.

Pilgrimage site for star-crossed lovers.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

This daunting 1st century fortress was purportedly the site of one of the most dramatic revolts of the Jewish-Roman wars.

The home of the Dead Sea Scrolls is an abstract modernist dream.

This permanent collection of preserved bodies taken from Irish bogs is one of the leading authorities on such morbid mummies.