Vaul's Anvil is a shrine of Vaul, the Elven god of smithing, which is situated in the heart of a volcano on the last island of the Dragon Spine a small archipelago of islands extending from the southern coast of Caledor in Ulthuan. There have been similar imitation shrines erected by the Dark Elves in Naggaroth and the Wood Elves in Athel Loren. During the Great Chaos Invasion, Aenarion the Defender and Caledor Dragontamer travelled to the Anvil to construct the Great Weapons that would be used to fight the forces of Chaos.
Only at Vaul's Anvil can one make the magical artefacts known as the Great Weapons and only with the relic known as Vaul's Hammer. Unfortunately Malekith's agents stole the Hammer during the Civil War and took it with them back to Naggaroth where it was used to construct Malekith's armour. Unfortunately for Malekith the Hammer is not as effective if not paired with the Anvil resulting in powerful armour but not as powerful as that constructed by Caledor Dragontamer.
However the theft of the Hammer has had an interesting effect on Asur politics: without the ability to create new Great Weapons, the number of Princes of Ulthuan are limited to those already in existence greatly limiting the amount of social mobility available to even the greatest of High Elf nobles.