Everyone is familiar with the idea of buried pirate treasure, and maps where “X marks the spot.” But is there any evidence of such a practice? Were there ever any pirate treasure maps as described? –Jimmy Breck-McKye, South Yorkshire, UK

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Did pirates ever bury treasure? It’d be strange if not–everyone else was doing it. For much of human history, if you had some covetable stuff you hoped to hang onto, couldn’t or didn’t want to put it in a bank or the equivalent, and owned a shovel, burial was Plan A. (That’s why, for instance, rural Britons still find pots of long-buried Roman coins.) Those who’d obtained their valuables under sketchy circumstances–say, while holding a cutlass to the previous owner’s throat–were only more likely, I’d imagine, to employ such DIY security measures. As one obvious requirement for this practice is a burial site that others aren’t likely to stumble on but you yourself can find again, it makes sense that pirates, who as seafarers dealt with maps regularly, might jot down reminders of where they left the goods.

Though it’s not where the premise first appeared, Robert Louis Stevenson’s Treasure Island was instrumental in planting the treasure-map concept in the popular consciousness. Some suggest a model for the title locale was Cocos Island, off Costa Rica; discovered in 1526, the island became a stopover for merchantmen, naval ships, and pirates. Cocos lore is bursting with primo pirate-story material: several vast hoards, vividly described and valued today in the high nine figures, supposedly buried there circa 1820 by captains William Thompson, Bennett Graham, and (my favorite) Benito Bonito; deathbed instructions from the principals on how to retrieve the stuff; cryptic diagrams etched into boulders; and so on. But efforts to locate the treasure turned up nothing. An 1850s expedition brought along one Mary Welch, who’d sailed with Graham and had a map purportedly showing the site of his trove. Key landmarks, however, had apparently disappeared in the intervening decades.

Art accompanying story in printed newspaper (not available in this archive): illustration by Slug Signorino.