thumb|[[Treasure of Villena, one of the most important prehistoric golden tableware findings in Europe]]
Treasure (from from Greek thēsauros, "treasure store") is a concentration of wealth — often originating from ancient history — that is considered lost and/or forgotten until rediscovered. Some jurisdictions legally define what constitutes treasure, such as in the British Treasure Act 1996.
The phrase "blood and treasure" has been used to refer to the human and monetary costs associated with massive endeavours such as war that expend both.
Searching for hidden treasure is a common theme in legend; treasure hunters do exist, and can seek lost wealth for a living.
Burial
Buried treasure is an important part of the popular mythos surrounding pirates. According to popular conception, pirates often buried their stolen fortunes in remote places, intending to return for them later (often with the use of treasure maps).
There are three well-known stories that helped popularize the myth of buried pirate treasure: "Wolfert Webber" (1824) by Washington Irving, "The Gold-Bug" (1843) by Edgar Allan Poe, and Treasure Island (1883) by Robert Louis Stevenson. They differ widely in plot and literary treatment but all are derived from the William Kidd legend. Stevenson's Treasure Island was directly influenced by Irving's "Wolfert Webber", Stevenson saying in his preface "It is my debt to Washington Irving that exercises my conscience, and justly so, for I believe plagiarism was rarely carried farther.. the whole inner spirit and a good deal of the material detail of my first chapters.. were the property of Washington Irving." One documented case of buried treasure involved Francis Drake who buried Spanish gold and silver after raiding the train at Nombre de Dios—after Drake went to find his ships, he returned six hours later and retrieved the loot and sailed for England. Drake did not create a map. Over the years, many people have tried to find the supposed remnants of Kidd's treasure on Gardiner's Island and elsewhere, but none has ever been found.