When a Welsh farmer dropped his keys on his property, he was determined to find them.

Ifor Edwards, 56, and his wife called their local heritage society, whose members came with metal detectors, armed and ready to find the keys on the farm in Whitchurch, England, roughly 50 miles south of Manchester. But the history enthusiasts uncovered something much more exciting than a pair of keys: 14 medieval coins that date back to the 14th and 15th centuries, the Shropshire Star reports.

“It is such a shock, you just can’t quite believe it,” Edwards said about the coins that date back to the reigns of Edward III, Henry V and Henry VI, according to North East Wales Coroner John Gittins.

“You realize those coins were there before they ever found America or anything,” he said. “We only bought the land three years ago, and nothing like this has ever been found before.”

The coins were discovered by metal detecting enthusiast Cliff Massey, 83, in June 2012. “He hadn’t ploughed the field for some time, and after he ploughed it I found two coins,” Massey told the Daily Post about the discovery. “I went the following day and found the rest of them in close proximity.”

The National Museum in Wales conducted studies on the coins, which found they were more than 90 percent silver. Four feature the face of Edward III, two of Henry V and eight of Henry VI. All are thought to have been lost or deposited on the land after 1465.

“The coin in the photo looks like a ‘groat,’ a type of currency used in old England,” coin appraiser Beth Weingast, a certified member of the Appraiser’s Association of America, told Yahoo Shine. “It may be the size of a half-dollar (a half-groat would be the size of a quarter), and, today, it might be worth anywhere from $700 to $800."

The Wrexham County Borough Museum, a nearby museum, has expressed interest in purchasing the relics. While Edwards hoped for an “unexpected windfall” from the coins, he still doesn’t know how much they’re worth. Any profits will be split between Edwards and Massey, the Shropshire Star reports.

Edwards, whose keys were found in a lawn mower, remains shocked about the tiny pieces of the past found on his land. “You just can’t believe you’re holding something that is 600-and-something years old,” he said.