Over thousands of years, this slot canyon was carved out of the bed of an ancient lake.

The world’s largest truck stop includes a barber shop, chiropractor, and a huge museum with antique trucks.

Lured here by the promise of tens of thousands in gold, Jesse James started a quintessentially American trend of robbing trains in-motion.

A wonderland of caves in eastern Iowa.

A place of great reverence for Trekkies everywhere, a hero's future birthplace.

The Beaux-Arts aquarium boasts a vast collection of saltwater and freshwater fish on an island in the Detroit River.

Monasteries on rock pillars, once accessible only by frayed ropes.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

Charnel house at the foot of Mount Sinai.

This sprawling bookstore spans four floors and has more than a million books in stock.

Oversized statues are just the tip of this nostalgic Americana roadside attraction.

A pop-culture attraction outside of Dyersville, Iowa, hits a home run.

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.

A striking glass tribute to two sisters who suffered during Scotland's "Killing Time."

This awkward aquarium sculpture is one of the strangest statues in Chicago.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

Fragments of architectural wonders from around the globe are embedded in the newspaper building's walls.

Each of these gorgeous, intricately decorated rooms is painstakingly crafted to the scale of 1 inch: 1 foot.

This historic hotel invented the chocolate brownie.

A complicated contraption for telling time by the moon.

The Cambridge pub where Francis Crick announced that he and James Watson had discovered the DNA double-helix.

Local legend says Isaac Newton built this footbridge without any screws, bolts, or nails.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

Hear the quietest sound from across the dome.