The fire of eternal light is an old fire pit that has been rebuilt and now has a white flame within that acts as an inextinguishable light source in the area it is built in. Building a fire requires the completion of Making Friends with My Arm, 35 Construction, and 66 Firemaking. When built, it gives 350 Construction and 300 Firemaking experience. The player must have a hammer, a saw, and a tinderbox in their inventory to build it along with the below items. The fires are located at three different locations: Falador Mole Lair, Lumbridge Swamp Caves, and Mos Le'Harmless Cave. A spade and a light source are required to gain access to the Falador Mole Lair. The fire pits located in the Lumbridge Swamp Caves and the Mos Le'Harmless Cave are a short distance from the entrance, meaning a light source shouldn't be necessary if the player is quick enough to build them although one is still recommended.
In the Lumbridge Swamp Caves, it also removes swamp gas so that any light source is safe.