Countless stories attempt to explain Poland's mysterious J-shaped trees.

Walk along the medieval fortifications that have been protecting Tallinn since the 14th century.

Traveling this mountain pass reveals quaint stone buildings, stunning Irish scenery, and a bridge said to grant wishes.

In 1977, an eccentric book lover formed a micronation for book lovers.

The castle that provided the setting for much of 'Monty Python and the Holy Grail' is now a pilgrimage site for fans.

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

Beloved children's TV characters freckle the German city's streets.

Now overgrown, these anti-tank barriers from World War II are sometimes called "dragon's teeth."

A neighborhood church's unusual abstract stained glass was the final project of avant-garde artist Jean Cocteau.

Liechtenstein's royal family calls this medieval alpine castle home.

The smaller of the three towers of San Marino is a former prison inaccessible from the ground level.

One of the largest squares in Europe contains an entire artificial island.

This amazing medieval fortress stands atop a promontory along the famous Cinque Terre.

The world's most active stratovolcano is almost always erupting.

A rare underwater observatory in the Caribbean that provides breathtaking views of vibrantly colored aquatic life.

The first location of the eventual video game giant.

Its columns were all carved from the same white oak tree.

The highest point in New Jersey is marked by a massive, if simply named, obelisk.

World War II-era bunkers are hidden under the beaches of this picturesque park, which is still scattered with wartime watchtowers.

The stone marker that Mason and Dixon placed at the eastern end of the famous north-south border they surveyed.

This field of concrete was once an active defense site armed with nuclear warheads.

This unique structure is the only one of its kind in Virginia.

This Virginia railway overpass is said to be haunted by a serial killer in a rabbit costume.

A 14-foot monument marks the resting place of two of the town's earliest residents—and one unknown soldier.