The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

Abandoned Italianate architecture on the coast of Maine.

The world's only and thus largest collection of its kind celebrates everyday wonder through simple umbrella sheaths.

A plaque on the side of a building is a small tribute to the woman who invented an iconic Berlin fast food.

Nine of the very few concrete ships ever made in the U.S. are beautifully decaying off a Virginia pier.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

A self-explanatory attraction allows fans to respectfully remember and honor a comedy legend.

An oddity shop inspired by the history of the circus.

Once the most densely populated place in the world, this island is now a ghost town.

This rare symbol of Eastern philosophy in the West has been created over years of painstaking construction by the local community.