This beloved Baltimore spot features caged dolls, a giant Pez collection, and many, many mannequins.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

Bizarre Cavern.

A free, public museum dedicated to the fascinating science of sight.

An artsy hidden staircase leads to breathtaking views of San Francisco.

This shop and studio is dedicated to the art of the book, from letterpress to bookbinding.

A spirited shopping experience.

Collecting 700 years of mechanical death-dealing, the NRA's sprawling gun museum is a revealing testament to the American obsession with armament.

An oddity shop inspired by the history of the circus.

This chilly Canadian hotel has a four-month lifespan due to the unusual material it's made of.

The world's first ice hotel is still one of the most elaborate and beautiful.

The world's largest man-made underground caverns offer unparalleled underwater wonders.

This intricate Hindu temple is the largest of its kind outside of India itself and was constructed like a giant puzzle.

You'll need cowboy boots to trek to this old-fashioned saloon nestled in a giant natural cave.

America's only nuclear missile silo open to the public.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

The tea room that pushed the boundaries of adorable straight into...we can't find the words.

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

The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

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

This massive subterranean fissure is known as the "underground Grand Canyon."