These fantastically named natural pools look like something out of a Scottish myth.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

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

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

This odd little museum holds exhibits on everything from blacksmith equipment to hair jewelry.

A 140-year-old castle with underground caves hidden in San Francisco.

Radioactivity still cause for concern at this urban explorer's paradise.

Tenacious mummies survived dental problems, eternal entombment, and more than their fair share of devastating fires.

One of the best absinthe distilleries in the United States.

A crumbling Beaux Arts monument to the Bay Area's age of rail.

A library and museum dedicated to typography.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

A still functioning vaudeville carousel that has operated for over a century boasts a colorful menagerie and past.

A walk down memory lane in the heart of one of San Francisco's most notorious neighborhoods.

A shop full of natural curiosities, carnivorous plants, and costumed taxidermied mice.

A library built during San Francisco's pioneer times is a student's retreat, bibliophile's sanctuary, and chess player's delight.

Russian history in San Francisco.

A tiny theater hidden in an alley plays a constant stream of short silent films for anyone willing to peer through the peephole.

The only theatre in the world constructed specifically for sound movement.

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

A nondescript building that's been functioning as a speakeasy for nearly a century and a half.

In this century-old literary safehouse, print is alive and well.