Guthix's altar is a cavern discovered by Guthix during the First Age. It's located at the bottom of the Tears of Guthix cavern, below even the Ancient Guthix Temple. The whole dungeon functions as a prayer altar, meaning that while in the dungeon the player's prayer points are regenerated at an equal rate to a prayer renewal potion, reducing the cost for prayer potions when killing monsters in the dungeon. Another altar is located by the Guthix dragon (an altar within an altar), which will recover prayer points by 400 points above the player's prayer level (this boost is only temporary and goes away after the extra points are used). However, this altar can only be used after the player has killed the Guthix dragon at least once.