Skull rocks are massive rock formations, cliffsides, or mountains in the shape of skulls. Fictional skull rocks often use the shape of a human skull, but occasionally other beasts such as dragons, leviathans, or other fictional creatures are used for the basis of their design. They are a worldbuilding element heavily used in fantasy worlds, particularly within the sword & sorcery and pirate genres. Skull rocks may be naturally occurring rock formations, may have been carved into their current shape, or be the result of some magical transformation. If used as a background element, they are related elements to giant skeletons and giant weapons, helping to set a tone for a world. Skull rocks may contain cavernous maws that lead to extensive cave systems. They may contain castles, crypts, evil temples, and/or catacombs. They are home to necromancers, cultists, and practitioners of the darkest and heaviest of black metal music.