In ancient Celtic mythology, the Thirteen Treasures of Britain were as follows:

1. Dyrnwyn the sword of Rhydderch Hael ; if any man drew it except himself, it burst into a flame from the cross to the point, and all who asked it received it; but because of this property all shunned it. and therefore was he called Rhydderch the Generous.
2. The basket of Gwyddno Garanhir; if food for one man were put into it, when opened it would be found to contain food for one hundred.
3. The horn of Bran Galed (the Niggard); whatever drink might be wished for was found inside it.
4. The chariot of Morgan Mwynvawr (the Wealthy); whoever sat in it would be immediately wheresoever he wished.
5. The halter of Clydno Eiddyn , which was in a staple below the feet of his bed; and whatever horse he wished for in it, he would find it there.
6. The knife of Llawfrodded Farchawg (the Horseman); which would serve four and-twenty men at meat all at once.
7. The cauldron of Dyrnwch the Giant ; if food were put in it to boil for a coward it would never be boiled, but if food were put in it for a brave man it would be boiled forthwith.
8. The whetstone of Tudwal Tudelud ; if the sword of a brave man were sharpened thereon, and any one were wounded therewith, he would be sure to die, but if it were that of a coward that was sharpened on it, he would be none the worse.
9. The garment of Padarn Beisrudd (Red-Coat); if a man of gentle birth put it on, it suited him well, but if a churl it would not fit him.
10. The pan and
11. The platter of Rhegynydd Ysgolhaig (the Cleric); whatever food was required was found therein.
12. The chessboard of Gwenddolau ; when the men were placed upon it, they would play of themselves. The chessboard was of gold, and the men of silver.
13. The mantle of Arthur; whosoever was beneath it could see everything, while no one could see him.

They were taken by Merlin to his cave for safekeeping until the time when they are again needed.