I'm reading the book Alan Turing: The Enigma by Andrew Hodges. The book is a biography on the mathematician Alan Turing, who is the star in the 2014 movie The Imitation Game where he was portrayed by actor Benedict Cumberbatch. While the movie focused mainly on Alan Turing's code-breaking skills, he is also famous for having thought much about Artificial Intelligence.
One thing Alan Turing is not famous for is his interest in the commodity silver. During the Second World War, Alan Turing wanted to protect is savings against imminent disaster in the case Germany would actually be able to invade Britain. His co-worker had seen how silver was the one thing that had gained in real value during the First World War. So Alan Turing decided to invest in physical silver.
Fast forward to 1952Apparently he imagined that by burying the silver ingots, he [Alan Turing] could recover them after an invasion had been repelled, or that at least he could evade a post-war capital levy. (In 1920, Churchill and the Labour party had both favored such a policy.) It was an odd idea.He bought two [silver] bars, worth about £250, and wheeled them out in an old pram to some woods near Shenley. One was buried under the forest floor, the other under a bridge in the bed of a stream. He wrote out instructions for the recovery of the buried treasure and enciphered them.
...the main point if the weekend was to make one last serious attempt to retrieve the silver bars. This time Don [Alan Turing's friend] had got hold of a commercial metal detector, and they went out to the bridge near Shenley in his car. Alan said, "It looks a bit different," as he took off his socks and shoes and paddled in the mud. "Christ, do you know what's happened? They've rebuilt the bridge and concreted over the bed!"
They tried for the other bar in the woods, finding that the pram in which he had wheeled the ingots in 1940 was still there, but without any more luck than before in locating the spot. Giving up both bars as lost forever, they made their way to the Crown Inn at Shenley Brook End for some bread and cheese.
According to this source, in 1944, 1946 and 1952 Alan Turing tried to find them and failed. No-one knows what happened to his buried treasure!