Open since 1938, this diner has kept its fountain, malt machine, and all the gum that greasers left beneath its counter.

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

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

Dramatic river bend surrounds a natural red-rocked pedestal.

Most-visited and most-photographed slot canyon in the American Southwest.

See massive fossils that are over 200 million years old in northeastern Arizona.

A self-built castle made by a mysterious man.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

Cat art as far as the eye can see.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

Museum preserving torture methods from the past.

A curious collection dedicated to human and animal anatomy and pathology.

Just another ancient, mysterious Irish stone circle.

Huge standing stones mark a site of megalithic mystery.

This ancient Irish religious site is covered in ancient carvings, many of which have barely aged.

These imposing walls and towers look more like the ruins of a fortress than a monastery.

Once the longest bridge in Ireland, this rusting span sits abandoned and overrun by nature.

This Irish show cave is said to have been the site of a Viking massacre that claimed 1,000 lives.

A tribute to the incredible generosity the Choctaw Nation showed the Irish people during the Great Famine.

An enigmatic monument to the Irish revolutionary who plotted an uprising against British rule.

Though they've since been renamed, these two streets hint at Dublin's darker days.