The Altar of Evil was the name given by the explorer Tinrilo x'Rilsam to an ancient shrine located on the planet Naboo. The Altar had been built at the site of a vergence in the dark side of the Force. Anybody visiting the place could feel its unnatural evil upon approaching the altar. The shrine was made of one large stone surrounded by three statues and decorated by one skull above an inscription in Aurebesh. During the Galactic Civil War, a Prophet of the Dark Side spent most of his time meditating at the Altar of Evil. By the time of the Battle of Yavin, Tinrilo x'Rilsam discovered the altar while exploring Naboo. However, the explorer afraid by the evil presence of the Altar and by the dark prophet decided to not push his exploration forward.
The Altar of Evil was a location in the 2003 video game Star Wars Galaxies, a massively multiplayer online role-playing game developed by Sony Online Entertainment and published by LucasArts, prior to its closure on December 15, 2011. The Altar of Evil was one of many unmarked points of interests on the planet Naboo. Following the release of the Star Wars Galaxies: Jump to Lightspeed expansion pack in 2004, rare data storage unit devices could sometimes be looted during space battles. One such data storage item, named "an Explorer's Log (2/8)," contained a detailed backstory for the Dark Prophet and the Altar of Evil.
The text in Aurebesh at the altar read "House Signs".