Hundreds of hidden passageways weave through the old quarters of Lyon.

Community bookshelf of 25-foot-tall book spines.

A hot dog stand where the heads are just as hot as the dogs.

A sculpture made of 10 Cadillacs as a monument to the “Golden Age” of the American automobile.

The only nuclear weapon assembly and disassembly plant in the U.S.

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

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

Ancient pueblos built into the base of a natural canyon wall.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

An enthusiastically interactive mining museum that won't let black lung ruin the fun.

The largest source of fossilized insects anywhere.

Self-built house and sculpture park where the creator can still be seen in a glass coffin.

The United States's largest hand-dug well is topped with a state-of-the-art museum.

Home to Hollywood history and a very special salt crystal.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

The celebrated eyesore created by starry-eyed sweethearts.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

Nicknamed the "Museum of Horrors," this French anatomical collection has been fascinating visitors for over a century.

A tiled, multi-level garden of survival in Lyon.

For hundreds of years, automatons moving to metallic music have been marking the passage of time.

Monsters and miniatures are held in equal esteem at this wondrous museum.

A colorful piece of contemporary art cheerfully clashes with Lyon's historical architecture.

One of the longest wooden benches in the world snakes around Geneva's Treille Promenade.

Artworks by loners, prisoners and the criminally insane.