A MAN who called in metal-detecting experts to find his lost keys on his farm was shocked when something much more valuable was uncovered.

Welsh farmer Ifor Edwards, 56, thought the best thing to do when he lost his keys on his property called Oak Farm in Bronington was to call in the Wrexham Heritage Society because they had metal detectors on hand.

The Shropshire Star reports that Cliff Massey, 83, found Mr Edwards's keys but also discovered 14 medieval coins from the 14th and 15th centuries, that likely come from the reigns of Edwards III, Henry V and Henry VI.

"It is such a shock, you just can’t quite believe it," Mr Edwards said. "You realise those coins were there before they ever found America or anything.

"You just can’t believe you’re holding something that is 600 and something years old," he said. "We only bought the land three years ago and nothing like this has ever been found before."

The coins are about 90 per cent silver and in good condition. While Mr Edwards is yet to get the coins appraised it is believed they could fetch between $700 and $800 each. Mr Edwards plans to split any proceeds with Mr Massey, the historian who found the coins with his metal detector.

Beth Weingast, a certified member of the Appraiser’s Association of America, told Yahoo! Shine that she believed the coins depict King Henry VI.

"Whoever ruled at the time also had their image imprinted on the currency and if you look closely, you’ll see that the king pictured here is smiling (or at the very least pleasant-looking), much like King Henry VI," she said. "His predecessor Henry V, scowled and had a thinner face, and during the reign of Edward III, people didn’t often use coins, instead trading items such as bread, cloth, beer, wood, or animal skins."

"Back then, many people bent and clipped the lettering off the coins and sold them at higher prices - the fact that this coin is unclipped means it may have been buried right after it was minted. Even if you saw this coin in a museum, it likely would have been clipped," Ms Weingast said.

The area in which Mr Edwards lives has been a good hunting ground for a treasure trove of rare artefacts. In recent years a ring-shaped silver brooch from the 14th century, an inscribed gold ring from the 17th century and a silver buckle from the 13th century have all been uncovered.