Limestone caves with spectacular showcase chambers.

A reproduction of earth's many biomes.

The world's largest military aircraft cemetery.

Established in 1925, Kiddie Park claims to be the oldest amusement park in the U.S. - a cozy little time warp nestled in a shady corner of the modern world.

An 18th century wonder of the world, lost in WWII, re-created at the Catherine Palace.

The past, present, and future of Russia's signature alcohol is remembered in the world's only museum dedicated to the starchy spirit.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

This Memphis recording studio launched the careers of Jerry Lee Lewis, Johnny Cash, and Elvis Presley.

America's post-nuclear-attack chambers of Congress.

An awe-inspiring mosque in Morocco with one of the tallest minarets in the world.

Mosaics, storks, and brothels—this ancient city has it all.

Traditional 11th-century outdoor tannery.

The oldest known university in the world is in Fez, Morocco.

A toweringly silly piece of modern art has been delighting locals since the 1980s.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Former villa and estate of James Deering developed to preserve native tropical forests.

One artist's love letter to his city and its citizens plays out across dozens of bright murals painted on the sides of decrepit buildings.

A layered tribute to the work of mosaicist Isaiah Zagar.

An enormous, inside-out glass globe built in 1935.

An interesting decoration on this historic site, this weathervane comes with as many legends as it does questions.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

Unsurprisingly, Holland is home to one of the most magnificent flower gardens in the world.

This centuries-old gothic monster has been converted into a sprawling, glossy bookstore.

Climb inside an iron crystal magnified 165 billion times its normal size.