Four Treasures of the Tuatha Dé Danann

In the Mythological Cycle of early Irish literature, the four treasures of the Tuatha Dé Danann are four magical items which the mythological Tuatha Dé Danann are supposed to have brought with them from the four island cities Murias, Falias, Gorias, and Findias when they arrived in Ireland.

Summary
The first recension of Lebor Gabála describes the Tuatha Dé Danann as having resided in "the northern islands of the world", where they were instructed in the magic arts, before finally moving in dark clouds to Connaught in Ireland. It mentions only the Lia Fáil as having been imported from across the sea.

One of the recensions of Lebor Gabála, Cath Maige Tuired and a separate text elaborate on these events. CMT and LG tell that there were four cities located on the northern islands of the world (i n-insib tūascertachaib in domain), called Falias, Gorias, Findias and Murias. "The Four Jewels" also refers to the cities, but appears to locate them at Lochlann and contends that the Tuatha Dé crossed the seas in their fleet rather than in a mist. The Tuatha Dé Danann—described as the offspring of Béothach son of Iarbonel—landed here to be instructed in the magic arts, embracing druidry (druidecht), knowledge (fis), prophecy (fáitsine) and skill in magic (amainsecht). Each island is said to have had its poet (fili) who was skilled in occult arts.

When the Tuatha Dé migrated to Ireland, they are said to have brought four magical instruments from these cities:

A. C. L. Brown and R. S. Loomis equate Lug's spear with the Lúin of Celtchar, which in Togail Bruidne Dá Derga is said to have been discovered in the Battle of Mag Tuired. There is however no sign of a literary tradition which connects the two weapons. A different spear belonging to Lug is the so-called spear of Assal in Oidheadh Chloinne Tuireann. It was brought back to Lug by the sons of Tuireann in atonement for their killing of Cian.