Thirteen Treasures of the Island of Britain
The Thirteen Treasures of the Island of Britain (Welsh: Tri Thlws ar Ddeg Ynys Prydain) are a series of items in late-medieval Welsh tradition. Lists of the items appear in texts dating to the 15th and 16th centuries.
Source: Wikipedia — Thirteen Treasures of the Island of Britain (CC BY-SA 4.0)