The human skull is an iconic image throughout history, and across cultures. Some use it as decoration, others as a warning.
It's also a common symbol of The Day of the Dead, where "calaveras" (Spanish for "skull") decorate houses and special altars.
Laurence King has just published The Book of Skulls ($14.95), curated by Faye Dowling, and featuring remarkable representations of these ghoulish masks from around the world.
Here are some of our favorite empty-eyed grins from its pages.