Decades after testing the polio vaccine on unwitting patients, this historic mental hospital sits in ruin.

A quirky bookstore hidden beneath a sea of whitewashed Greek villas.

Colonial architecture meets urban art in this sprawling open-air gallery.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

Abandoned silver mine strewn with wrecked and twisted structures.

Holding the most bodies of any cemetery in the United States.