This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

A gorgeous garden oasis with winding paths, stone bridges, and a troubling history.

This lovely little bridge hidden in a Switzerland gorge is essentially a fairytale.

Walk through living pictures and music in the Cathedral of Images.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

This short pedestrian span is also known as the "Fairy Walking Bridge" because it looks almost magical.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

This razorback ridgeline has doubled as a scenic drive since the early 1900s.

This historic stone bridge has an entire neighborhood clinging to its sides.

Ancient paintings known as the "Sistine Chapel of Cave Art."

A 14th century bridge built as a fortress, where the devil lurks on one of its towers.

A gravity-defying "devil's bridge" that has a surprising architectural feature for its stability.

Scotland's oldest medieval bridge is also among the last reminders of early medieval Aberdeen.

A breathtaking bridge that crosses a vast gorge over a river's torrents, and has a tale of a devil architect attached.

An architectural marvel that spans the Arda River, and has stories of a haunted past.

A serpentine highway twists and turns over the treacherous Norwegian Sea.

From carts to cars, this leftover Roman bridge in France has managed to survive for centuries.

A dangling church built over a Colombian gorge.

Germany's Glienicke Bridge has a shady history of clandestine meetings, espionage, and spycraft.

Erected in 1697 this Philadelphia bridge is the oldest surviving roadway bridge and perhaps the oldest stone bridge in the United States.

The latest in a series of long glass bridges suspended at terrifying heights.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the century.

This study room in the New York Public Library saw the creation of one of contemporary America's greatest traitors.

A double agent hid information for the Soviet Union beneath this bridge for more than 20 years.