This frozen tunnel in central Alaska is both an engineering feat and a valuable climate classroom.

A 19th-century time capsule of travel, fiction, and historic texts still available to the public.

Mausoleums, astronomy, and animatronic dinosaurs at this memorial to an assassinated American president.

A huge work of Burning Man-inspired outsider art on the grounds of a California winery.

A collection of outdoor mystical statues paying homage to indigenous Australians and ecological stewardship.

A million and a half tons of earth were used to create one of the world's largest land sculptures.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

A natural wonder in south Denmark.

The most famous location in China was home to whole dynasties worth of imperial rulers.

North Korea's massive art and propaganda factory now has an official gallery space in Beijing.

Ming Dynasty necropolis raided during the Cultural Revolution.

At Monet's beloved home you can still see the Japanese bridge, waterlilies, and weeping willows that were the subjects of some of his most iconic paintings.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

This Austrian museum celebrates the work of famous forgers and their inimitable imitations.

The Habsburgs' royal collections of art and wonders.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

Handsomely crafted representations of our round planet.

No one knows how this Pacific Northwest spruce tree came to have so many trunks.

A collection of colorful dinosaurs hidden in an actual rainforest.

Taking the 3D art experience far beyond blue and red glasses.

Portlandia is the second-largest copper repoussé statue in the United States.

This extravagant Art Nouveau rest stop features a million-dollar view of the Columbia River.

Their motto is, "We've been bonkers for hats even longer than you have!"

The world's smallest park was dedicated in 1948 as the only colony for leprechauns west of Ireland.