Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

A formerly abandoned mental institute, now back in business.

A museum devoted to bringing to light forgotten or neglected histories through exhibitions, education and public programming.

A semi-scholarly approach to sex.

Reverend Jen's unique museum/living room showcases her troll collection.

Remnants of a storybook amusement park hidden behind a strip mall.

Collapsing castle on the Hudson river was once the storage site of military surplus business.

A terrific purveyor of natural history objects and curios.

Tucked in the back of this amazing antique store is an important piece of medical history.

A crumbling hospital from the 1850s on Roosevelt Island.

Stroll through a wonderland of stupendous moss-covered trees.

A French chateau, failed utopian community, odd museum, and Stonehenge replica in rural Washington State.

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

Site of the greatest known waterfall that ever existed.

A huge musical sculpture and other art installations on the National Oceanic and Atmospheric Administration grounds.

Quirky castle designed by the American actor best known for portraying Sherlock Holmes on stage.

Around 100 sculptures from artists all over the world decorate the hiking trails surrounding this locale.

A beautiful Victorian-era cemetery, complete with a miniature village.

World's first "penitentiary," meant to be humane, drove men insane.