This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

The secret city built by the Manhattan Project.

Once an unstoppable source of gold and silver, this town came to a grinding stop when the groundwater proved deadly.

Costumed elves and mountain bikers co-exist peacefully at this abandoned Christmas-themed adventure park.

Montreal's giant farmer's market is a foodie's best friend, especially in the winter months.

A ruined castle has more than its fair share of legends and ghost stories.

The view that inspired the scenes of Dracula's first landing in England.

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

Volunteer-run library dedicated to exploring five decades of activism history.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

An 18th century wonder of the world, lost in WWII, re-created at the Catherine Palace.

The gloomy ruins that inspired Bram Stoker to bring Dracula to life.

Remote, volcanic island that Darwin, Hooker, and the Royal Navy shaped into a thriving, artificial ecosystem.

A sculpture that resurrected the only tree standing following the devastating 2011 tsunami.

Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

An old-timey medicine shop that once served Chinese laborers during the Gold Rush is still open for business to this day.

A mysterious castle built as a monument to lost love.

California's oldest existing theater building hosted an impressive cast of celebrities, including hosting Mark Twain's first lecture.

A daily pyrotechnic celebration marks a beloved tradition during Valencia's festival season.

This historical air terminal in Houston is slowly becoming an aviation museum dedicated to the city's aeronautical history.

A preserved 18th century steel factory.

Museum dedicated to literary greats of the Romantic Period is also the home in which Keats met his untimely end.

A massive tribute to this small county's top agricultural product.

A military vehicle collection, showcasing how war transportation advanced from horse drawn artillery to self propelled cannons.