The rare gold leopard coin, which was minted in 1344. (Image credit: <a href="https://creativecommons.org/licenses/by/2.0/" target="_blank">CC BY 2.0</a>)

Saving for a rainy day is not a new idea. In 2021, archaeologists turned up a whole horde of hoards: stashes of coins and other valuables left behind for whatever reason and never used again. These treasures turned up in a Polish cornfield, in a meadow in New England, in a town in Denmark. They were left by royals, pirates, chieftains and people who will forever remain anonymous. 

Many of these hoards were discovered by lucky amateurs with metal detectorsor sharp eyes. Some date back as far as 1,500 years. From good luck pennies to the biggest Anglo Saxon hoard ever found, here were some of the year's most noticeable treasure troves.

Medieval gold coins and rings from a Polish cornfield

In 1935, the biggest hoard of coins from the Middle Ages ever found in Poland was unearthed in the village of Słuszków. In late 2020, a visitor returned to the town to learn more about that hoard, and they ended up finding another one.

Adam Kędzierski, an archaeologist at the Institute of Archaeology and Ethnology at the Polish Academy of Sciences, found the treasure trove of goldrings, silver ingots and silver coins after a tip from a local priest led him to a cornfield. There, he found a ceramic vessel full of buried treasure. The riches date back to 1105, and they may have belonged to Poland's first royal family. One of the gold rings is engraved "Lord, may you help your servant Maria," in Cyrillic, and might have been worn by Dobroniega Maria, a daughter of the Prince of Kiev, Vladimir the Great, Prince of Kiev, who was married to the Polish price Casimir the Restorer. 

Roman-era silver coins in Turkey

Two bent and scuffed gold coins found in Norfolk County, England, were issued by King Edward III during a time when Black Death was ravaging the country. 

The coins, found by a metal detectorist, were part of an effort to reintroduce gold coins to England after centuries of using silver. One, known as a "leopard," is 96% pure gold and was part of a run of coins issued only between January and July 1344, making it a rare find indeed. Leopards failed as coinage because they were too costly to produce and were overvalued compared with silver, according to England's Portable Antiquities Scheme. Whoever owned the coins was a wealthy individual, though: Together, the gold pieces were equivalent to $16,700 (12,000 British pounds) in today's money.

Roman offering for safe passage

More than 100 Roman-era coins found by a river in the Netherlands were likely offerings for a safe passage across a ford, archaeologists revealed in July. 

Amateur treasure-hunters discovered the 107 coins, many festooned with military imagery, by the Aa River near the town of Berlicum in 2017. No one knew why the coins were there until this year, when historian Liesbeth Claes, an assistant professor at Leiden University in the Netherlands, took a hard look at the clues: The coins were scattered over a large area and were minted over a period of 200 years, suggesting they were dropped one-by-one rather than buried as a hoard. They were also small denominations, mostly bronze with just a few pieces of silver. Finally, Claes and her colleagues found an old document mentioning that the spot where the coins had been found had once been a ford. Everything clicked. The coins had likely been dropped as a good-luck gesture by travelers, who dropped them in hopes of making it safely across the river, much as someone today might toss a penny into a wishing well. 

Gold treasure found by freedivers

A couple of vacationers picked up more than souvenirs from the bottom of Portitxol Bay, Spain, in August. The brothers-in-law, Luis Lens Pardo and César Gimeno Alcalá, were free-diving with rented snorkels when they spotted a glimmer of gold on the ocean floor. 

The glimmer turned out to be 1,500-year-old gold coins, 53 of them, which the divers reported to the authorities. The coins dated to the latter days of the Western Roman Empire, between A.D. 364 and 408, and sported the faces of several emperors: Valentinian I, Valentinian II, Theodosius I, Arcadius and Honorius. There was no shipwreck nearby, but remnants of iron and wood nearby suggested the coins may have originally been buried within a small chest. 

Iron Age chieftain's hoard

Newly-minted metal detectorist Ole Ginnerup Schytz was surveying a friend's land in Vindelev, Denmark, with his new metal detector when he experienced the epitome of beginner's luck: He turned up a hoard of coins, jewelry and ornaments dating back to the Iron Age. 

The stash contained 2.2 pounds (1 kilogram) of gold. The discovery kicked off a full archaeological excavation, which revealed remnants of a longhouse around the hoard, suggesting that the spot was the site of a powerful village during the sixth century, when the gold was buried. 

Among the treasures were Roman coins melted into jewelry and several gold discs called bracteates, one of which may depict the Norse god Odin. 

The largest Anglo-Saxon hoard ever

A metal detectorist in West Norfolk, England, turned up the largest hoard of Anglo-Saxon coins ever found in the country — a discovery that ultimately triggered a crime. 

The anonymous treasure-hunter turned up 131 coins and four golden objects over the course of six years. That person reported the coins to the authorities, as is required in England in cases where the find might be more than 300 years old and made up of at least 10% precious metal. But another metal detectorist, police officer David Cockle, dug up 10 of the coins and illegally sold them. Cockle was sentenced to 16 months in prison, and two of the 10 coins he sold have not been recovered. 

Black-market dealings aside, the coins remain a spectacular find, according to the British Museum. They were buried around A.D. 600, at a time when what is today England was made up of several independent Anglo-Saxon kingdoms. The hoard is the largest ever found from this era, topping the 101-piece Crondall hoard discovered in 1828.  

Originally published on Live Science.