In a grove of fast growing walnut trees outside Paris, Illinois, a marker shares the story of a fictional road building culture.

In an alley not far from where two great highways meet, byways of a very different sort are honored.

A county library in rural Ohio houses one of the finest mineral collections in the world.

Modeled after the labyrinth in Chartres Cathedral, this small-town Indiana memorial labyrinth sits half a world away.

The first spinning jail built in the United States is the only one that still turns.

Low-frequency noise compared to an idling train can only be heard by some of this industrial town's residents.

Display that gathers the basic elements of the universe in one convenient location.

One man's vision and a labor of love of many.

This abandoned dream castle and its cemetery look out over the city that once inspired their creation.

This lovely university observatory continues to sit abandoned since its potential savior was sent to jail for fraud.

Small, privately owned island divided between Michigan and Ohio with abandoned vacation homes and a derelict lighthouse.

One man's attempt to create an artistic wonder on a run-down block in Detroit.

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

Stunning wetlands ablaze with pink lotus flowers.

A spectacular cave and a beguiling lake.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

Dramatic river bend surrounds a natural red-rocked pedestal.

A 16th-century horror show built in a lovely Italian garden.

An old vending machine serves up unpredictable beverages from its seemingly magical insides.

World's largest collection of serial killer artwork and other macabre exhibits.

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

The world's highest and most dangerous infinity pool lies at the precipice of Victoria Falls.

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

A massive underwater sinkhole made famous by Jacques Cousteau.