You never know where history hides. It could lurk unobtrusively in a river-bed sand or a dumpster.

In recent weeks, there have been reports about some startling finds of artefacts from the most unusual of places. Two swords that may have belonged to the Vikings have turned up from riverbeds.

In January, some workers were desilting the Vistula River near the city of Wloclawek in Poland and Oophs!, they picked up a 1,000-year-old sword. Rusted, of course, but otherwise in good shape. Wojciech Sosnowski from the archaeology department at WUOZ in Torun, Poland, calls it a “major archaeological sensation”. X-ray imaging has revealed the word ‘Ulfberht’ on the artefact, a marking that is found on medieval swords in northern Europe.

Treasure hunter Trevor Penny turned lucky when he was “magnetic fishing” in the Cherwell River in Oxfordshire, England, when his powerful neodymium magnet latched onto something hard and rust — a Viking sword which may have severed necks around 850 AD.

But the cake goes to a find in 1980. In a dumpster at Newcastle University, a worker chanced to find a trove of rare seashells that are believed to have been collected by a person named George Dixon, a crewmember on board Captain James Cook’s ill-fated third voyage. While Cook was killed by a Hawaiian king he tried to kidnap, little is known of Dixon, except that he had been collecting natural pieces of the natural world for a connoisseur back home — to whom he dispatched the shells. The shells were preserved by a lecturer of the University, whose descendants have recently donated them to English Heritage, which preserves such things.