19th century tunnels burrowed under Liverpool.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

The unusually large seat sits atop the base of a ruined temple.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

A spherical "micro-nation" in the heart of Vienna.

Handsomely crafted representations of our round planet.

A wunderkammer hidden on the top floor of the Hartford statehouse.

The former home of Samuel Clemens and family remembers the happiest period of the author's life.

The early American colonists were such ferocious drinkers the law actually required every town to have a tavern.

A world-class collection of mechanical musical instruments and automata.

100 massive sculptures in the Hudson River Valley.

Reclaimed by nature, the ruins of Doodletown, New York are remnants of a town consumed by a state park.

The world's largest public collection of PEZ memorabilia.

Astonishing collection of helmets, scientific instruments, and medical models.

Yale University's home for rare works, including the mysterious Voynich Manuscript.

This massive boulder is either a unique rock formation created by glacial melt or a magic energy vortex.

Take a sea tractor to the Art Deco hotel on the island that inspired Agatha Christie.

A unique waterfall that some believe attracts the fairfolk.

A fantastic castle rumored to be the birthplace of King Arthur.

Wooden sleds have replaced donkeys to cart goods around this utterly charming car-free village.

This tangled English forest looks like something right out of a fairytale.

The ruins of an 11th-century Norman castle with a rare, perfectly circular shape.

400-year-old garden, restored to beauty.