These sub-farmland caves are home to a majestic stalactite known as the "Crystal King."

A storefront museum in Asbury Park honoring the Jersey Shore’s deep history of mystery—including the Jersey Devil.

These tourist trap caverns are said to be the former home of a legendary Pennsylvania Hermit.

One of the steepest streets in the United States makes an intriguing challenge for cyclists.

A once grand hotel is being retaken by the wilderness it once capitalized on.

A luxurious 1880s hotel with its fair share of Tiffany stained glass, Edison electricity, and of course, ghosts.

A haunted hill that supposedly defied gravity.

Read between the lines of the subway map to find the hidden abandoned Civil War fort.

A mysterious castle built as a monument to lost love.

House of vintage taxidermy and Steampunk sculptures in a quiet Pittsburgh neighborhood.

The world's longest known cave system.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

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

A layered tribute to the work of mosaicist Isaiah Zagar.

A terrific purveyor of natural history objects and curios.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

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

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

A former copper mine which became a truly unsuccessful prison.

The ruins of an abandoned 18th-century town that is slowly being reclaimed by the forest.

Known as one of the most climbed mountains in the world, this barren peak is permanently bald thanks to an anti-wolf fire.

America's oldest archaeological site or a muddled case of wishful thinking.

Located just behind a quiet residential neighborhood, this is ground zero for the Salem witchcraft hysteria of 1692.

A collection of full-size movie monsters opened to the public.