An abstract monument to a symphonic composer.

This irregularly shaped sea fortress has defended not one but three different sovereign states.

Legend has this precariously placed rock was placed by giants. Science has another explanation.

This fantastical icy castle is built anew every winter.

Architecturally stunning library serves as the hub of Finnish scholarly life and culture.

A subterranean house of worship carved right out of the bedrock.

Menacing or in memoriam, the Silent People and their meaning are left to interpretation.

Among the oldest structures in Madrid, these Moorish walls once guarded the medieval city of Mayrit.

Inside this McDonald's you can dine on your Big Mac and fries next to a 2,500-year-old Roman wall.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

Filled with goldfish swimming in a shallow pool of sea water, this ancient crypt is more wishing well than burial site.

The true age of this ancient stone circle is unknown, but its stunning vista isn't in question.

Amazing vistas await visitors to this stretch of coastline.

400 million years of erosion shaped these fascinating seaside caves, which made an appearance on 'Game of Thrones.'

These unknown Bronze Age earthworks are believed to be ancient burial mounds.

This massive basalt sea stack stands obtrusively from the rocky coastline.

Hidden in Carnfunnock Country Park is a lasting testament to the Normans who once settled in the region.

Local legend says there's treasure hidden within its crowded graveyard.

A replica memorializes the site where women were punished after the last witchcraft trial in Ireland.

This massive monument has been telling the time for 150 years—at a slight angle.

This mysterious Bronze Age standing stone has become a place where couples profess their love.

A Victorian marvel of engineering is now a 21st-century tourist attraction.

Step into Narnia at this small park featuring statues from "The Lion, the Witch, and the Wardrobe."

A medieval abbey featured on 'Game of Thrones' that dates back to the 12th-century.