Secret donors are hiding money for Twitter followers to find. BBC Culture looks at a children’s book that went viral long before 140-character treasure hunts.

In 1979, the British artist Kit Williams buried a golden hare in a Bedfordshire hillside. Over the following three years, the jewelled pendant became the focus of an international craze, as treasure hunters followed clues hidden in a children’s book to uncover it.

A Swiss family spent their life savings in their search, while Japanese, Danish, German and American hunters were convinced they would find the treasure in Big Ben or Edinburgh Castle. One man wrote to Williams every day, in letters of up to 7,000 words, detailing where he thought the hare could be.

Long before the current fad for hiding cash in public places, with Twitter accounts like @HiddenCash dispensing clues and causing frenzied scenes in the US, Williams sparked a global obsession – and became a virtual recluse in the process.

The artist created his hare out of 18-carat gold, encrusted it with ruby, mother of pearl and moonstones and sealed it inside a ceramic casket to foil metal detectors. He embedded complicated clues in 15 paintings which he published as the children’s book Masquerade. The eyes and hands of his characters gestured toward letters in the text that could be joined together into sentences that suggested the pendant’s location.

The book sold 2m copies, with hundreds of readers claiming they had solved the riddles and found the hare. Yet it was eventually recovered not by an avid treasure hunter, but by the business partner of Williams’s former girlfriend, who knew its general location.

Even after its discovery, treasure seekers set out armed with shovels and maps. TV presenter and author Bamber Gascoigne, who witnessed the burial of the pendant, said in his book Quest for the Golden Hare:  "Tens of thousands of letters from Masqueraders have convinced me that the human mind has an equal capacity for pattern-matching and self-deception. While some addicts were busy cooking the riddle, others were more single-mindedly continuing their own pursuit of the hare quite regardless of the news that it had been found.”

The Hidden Cash scavenger hunts have now made their way to the UK and Canada, and the anonymous Californian millionaire who was the first to stash money appears to have caused mass hysteria to match the obsession sparked by Masquerade. Here, Williams describes the lengths to which treasure hunters went in their search for the golden hare.

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