In late 2018, walkers enjoying a stroll along Barafundle Bay (pictured) in Wales came across something rather mysterious. Sticking out of the sand were timbers, a windlass and even an anchor, in what turned out to be a wreckage from a ship. However, local accounts soon revealed that the wreckage had first been spotted decades before and that it becomes visible every 10 years or so when the sea and weather conditions are just right. Historians believe that the wreckage likely belongs to the Sea King, a trade ship that went down in 1896. The ship was travelling from Cardiff to Brazil carrying 2,000 tonnes of coal, when it ran into rocks and began to fill with water. Three crew members died in the disaster, though the ship's Norwegian captain Gattorn Olsen managed to save the rest of his men by running the ship ashore.

A Thai fisherman made an extremely rare discovery while walking on a beach in Koh Samui in October 2019. So what exactly had he found? The fisherman had stumbled upon a lump of ambergris, better known as whale vomit. A highly sought after ingredient in the perfume industry, the rarity of ambergris makes it extremely valuable. Previously earning around $13 (£10) a day, the fisherman is set to net a whopping $320,000 (£250k) thanks to his chance find. In 2016 three friends fishing off the coast of Qurayat in Oman struck gold after finding a large lump of the stuff, which was valued at nearly $3 million (£2.34m). 

Rivers where you can still prospect for gold

In 2012 gold prospector Vincent Thurkettle came across a chicken egg-sized object on the seabed at Moelfre, Wales. After closer inspection, it became apparent that he'd discovered a 23-carat nugget of gold, which at 3.4oz (97g) is actually the largest nugget ever found in Britian. Vincent kept his find a secret until 2016, when news of his find caused swarms of people to fill the beach in a matter of days. The gold is believed to be part of the haul from the Royal Charter, which sank during a hurricane in 1859. The ship was on its way to Liverpool from Australia when the disaster occurred, killing 450 people. It was carrying £100 million in gold, of which £1 million ($1.3m)-worth remains undiscovered, an attractive prospect for budding treasure hunters. However, any valuable finds from the wreck are property of the Crown and Vincent had to surrender his treasure, worth around £50,000 ($64k).

Staying in Wales, in 2019 a member of the public discovered a long-buried piece of history on a beach there. The remains of a 45ft (14m) vessel were made visible thanks to a period of bad weather. The boat was "tentatively" identified as the Endeavour, which had disappeared without a trace in October 1854. Not to be confused with Captain Cook's Endeavour, this 35-tonne vessel was a wooden sloop (a sailboat with a single mast). It was used for trade along the Welsh coastline, before it was destroyed after being caught in gales over 150 years ago. Thankfully it was reported that all of the crew made it off of the ship alive.

A poor Indonesian woman made a life-changing discovery in 2013. While digging for oysters in Gampong Pande village, Banda Aceh, she came across a strange wooden chest that was covered in coral and shells. While it was clearly very old, nothing could have prepared the villager for what she was about to find inside. The chest was filled with coins dating back to between 1200 and 1600. The treasure had most likely been buried with a 13th century ruler at the ancient graveyard nearby, and had been washed up following the 2004 tsunami that devastated the area. None of the locals had dared to disturb the graves previously due to fears of retaliation from spirits, but the discovery of the chest lead to a goldrush in the area.

Robert Felce is no stranger to finding treasure on the beach, having previously discovered centuries-old hand grenades near the wreckage of a former pirate ship in Cornwall. In May 2019, at the same spot at Dollar Cove near Helston, he found the remains of a sword, probably from the same 335-year-old shipwreck. Identified as part of a cutlass, it would originally have been owned by a sailor, soldier or perhaps a pirate. The sword came from the wreckage of the Schiedam, a Dutch trade ship (similar to the one pictured) that was captured by pirates off the coast of Gibraltar in August 1683. It was then taken by the Royal Navy who used it to transport military supplies, horses and civilians following the abandonment of a colony in Tangiers, Morocco. The ship got caught in a storm on its way to England, becoming wrecked off the coast of Cornwall in April 1684.

Back in 1974 a family holidaying in Cornwall chanced upon a copper ingot at Loe Bar Beach. The discovery was key for maritime historians, who believed it could be a vital clue in helping to locate the wreckage of St Anthony, a Portuguese ship that had become lost at sea in 1526. A team of experts were sent to investigate the area, and the remains of the St Anthony were discovered in 1981. The ship's timbers hadn't survived due to the rocky gullies on the seabed, and all of the artefacts recovered were in terrible condition, having been worn away over almost five centuries. The St Anthony had become wrecked on route from Lisbon to Antwerp, after the anchors of the 350-ton ship had snapped. The captain tried to deliberately run it ashore, but hit a hidden reef. Tragically, half of the crew went down with the ship. 

Discover the world's most valuable stolen treasures

Cornwall is a veritable trove for treasure hunters, thanks to the numerous shipwrecks that have occured in the local waters over the centuries. One such find took place back in 1996, when a lucky couple noticed a shiny object at Loe Bar Beach. The item turned out to be a gold coin, dating back 600 years. The coin, or ducat, dated back to the reign of King Ferdinand I, who ruled Aragon, Spain, from 1412 to 1416. Measuring 22mm in diameter, the coin had the mark of Giancarlo Tramontano, the last mintmaster of Naples appointed by Argonese rulers. It was put up for auction in Cornwall in 2017, with a guide price of £500-800 ($640-1020).

Chon Carlile had the rather unusual hobby of searching for skulls, rocks, and shark teeth on his local beaches. In June 2019 this part-time hobby paid off when he came across what he first thought was a piece of rubbish sitting in the sand at Myrtle Beach, South Carolina. It turned out to be a tooth. However, as he would soon find out, this large molar, dating back over 10,000 years, belonged to something a little more impressive than a shark. The tooth turned out to be from a mastodon. These elephant-like creatures once roamed the forests of North and Central America, before becoming extinct thanks to over hunting by humans. The largest specimens could reach up to 9.5 feet tall, and weigh up to 8 tonnes.

In March 2018 Juliano Turner and her son happened upon a a very well preserved shipwreck at a beach near St. Augustine in Florida. Experts believe that the 48-foot section was part of a cargo ship dating back to the 1830s-1860s, which originated from the southern United States. However, as the shipwreck technically belonged to the state, researchers didn't have permission to move it, and so faced a race against time before it was reclaimed by the sea. Experts rushed to document the find, hoping to create a 3-D model of the whole ship. Hundreds of fascinated locals flocked to the beach to take a closer look at the mysterious piece of history. Thankfully the state of Florida stepped in just in time, and the wreck was safely moved.

Treasure hunter Frank Abreu made a very surprising discovery in the Bay Area of San Francisco in May 2018 when he found three gold Roman coins. Fearful of being accused of staging a hoax, Abreu kept the discovery to himself until he got confirmation from coin dealer Eric Davies that the coins were "85-90% authentic Roman". By this time the number of Roman coins found had increased to seven. But the mystery remains: what were Roman coins doing on a beach in America? Frank is determined to find the answer, stating, "The implications that there could have been Romans here in the United States prior to Christopher Columbus is crazy."

The most incredible metal detector finds ever

In the 1970s the remains of a WWII fighter plane were revealed on a beach in Wales. The discovery of the Lockheed P38 Lightning was deemed "one of the most important WWII finds in recent history". The American fighter plane, known as the Maid of Harlech, crashed off the coast of Wales in 1942, when its engine cut out during training exercises. Remarkably, the plane's pilot, Robert Elliott walked away without any injuries. The historic remains have actually been uncovered three times, in the 1970s, in 2007 and then in 2014, when weather conditions were just right. Due to its historical importance, the Welsh government has given it protected status, the first aircraft wreckage site in the UK to have this. With no plans to salvage the wreck, its exact location is being kept secret.

Jon Gopsill was enjoying a walk along the beach at Stolford, Somerset in December 2019, when a startling discovery was made. However, while Jon may have been the one who called it in, it was actually his dogs, Poppy and Sam, who found the treasure, which turned out to be a 5ft 5in (167cm) long fossil. After it was carefully recovered from its sandy resting place, experts got to work trying to identify the mysterious find. The 190-million-year-old fossil, given the nickname "Poppy" after its canine finder, was revealed to be that of an ichthyosaur. These dolphin-like reptiles lived during the Triassic period, becoming extinct around 90 million years ago. They could grow up to 46 feet (14m) long, and had strong, sharp teeth. South West Heritage Trust have said that the exciting find will eventually go on display at The Museum of Somerset.

When one of the world's largest shipping container ships, the MSC Zoe, was caught in a storm in January 2019, it caused a huge stir for locals in the Netherlands. Nearly 300 containers were lost, with dozens becoming washed up on Dutch beaches. Local law allows members of the public to keep whatever treasure they find on the beach, so hundreds of treasure hunters flocked to the coast with the hope of finding something valuable. Despite government warnings to stay away from the containers, as some contained toxic materials, beachcombers posted images of their finds on social media. This 'treasure' included IKEA furniture, toys, clothing, and TVs. Pictured is one of the containers being salvaged from a beach.

 Three hundred years after a Spanish fleet of ships sunk just off Florida's Atlantic coast, its precious cargo is still being discovered. Treasure from a sunken 1715 Spanish fleet has been washing up for years, and in 2015, diver and treasure hunter William Bartlett was exploring the coast near the site of the shipwreck when he made a life-changing discovery. After coming across a couple of gold coins using a metal detector, Bartlett and two friends decided to explore the nearby waters more thoroughly. The result? Over the next few days they found 350 gold coins, worth $4.5 million (£3.51m). A similar discovery had been made a few months earlier by a family of treasure hunters, who walked away with $1 million (£780k) in gold coins and artefacts from the wreckage site.

In January 2019 an ancient funeral mask washed up on Melbourne Beach, Florida. Thought to be between 10,000 to 12,000 years old, the mask was believed to have been created by an ancient South American civilization, and would have looked similar to the one pictured. While mainly made of copper, it also contained traces of gold, silver and iridium, a material found in meteorites. What makes the mask even more important, is the fact that some experts believe it could be part of a treasure haul from a convoy of ships that sank in 1715. Eleven Spanish ships were returning from Cuba when they were hit by a hurricane. The treasure onboard, including the funeral mask, all sank with them. The value of this treasure today? A whopping $4 billion (£3.1bn).

Read more: The most brilliant treasure finds of the past decade