The ancient tomb acts as a calendar that keeps perfect time.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

Ireland's most remarkable collection of these curious cone-shaped houses is worth the buzz.

Achill's most recently abandoned village dates back to to the Age of Enlightenment.

Send a postcard while vacationing with Satan.

Georgia's highest point was given its strange name thanks to a simple translation error.

Elvis's own personal tropical hideaway.

Every day a troupe of pampered water fowl walk the red carpet to their favorite fountain.

At 135 years old and counting, this historic print shop is heaven for poster nerds and music buffs.

The world's longest known cave system.

Enjoy an overnight at an old haunted B&B site of the Borden family murders.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

Sloth rehabilitation center in the jungle of Costa Rica.

This neon blue river gets its color from a unique mix of bacteria and volcano minerals.

Mesoamerican monoliths and zoomorphic stones covered in royal visages, ancient mythology, and grand celestial events.

An important Mayan religious and trading center dating back to 200 BC.

This 16th-century church now has a heavenly second life as a cultural hub of Pátzcuaro.

Climb through the life of a Mexican hero as you ascend a 130-foot statue.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

America's first public mental health facility.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

A monument celebrating the idea of reaching inaccessible places.

A small poultry graveyard in the courtyard of a popular Key West watering hole.

The highway's southernmost spot is a beloved local attraction.