Deemed to be one of the most sacred objects mentioned in the Bible, the Ark of Covenant is the definition of a long-lost treasure. It’s estimated that it was built around 3,000 years ago by the Israelites and is linked to many miracles in the Old Testament. The gold-covered chest can be spied in a lot of biblical artwork, such as The Ark Passes Over the Jordan, which was painted by James Tissot in 1902.

Pirate Edward Teach, better known as Blackbeard, terrorised the Caribbean in his flagship the Queen Anne's Revenge for years during the early 18th century, looting ship after ship, and collecting many treasures, from gold bars to fine jewellery worth millions of dollars in today's money. The buccaneer allegedly buried the bulk of it on islands around the Caribbean and parts of North Carolina.

While some of Blackbeard's booty was found with his shipwreck in 1996, including a wine glass stem decorated with diamonds and tiny gold crowns, treasure hunters believe most of the riches are still out there somewhere. If they really exist they are most likely to be buried on one or more of Blackbeard's stomping grounds. They could include Blackbeard's Castle on the US Virgin Island of St. Thomas, and Plum Point in North Carolina.

Discover who were the richest pirates of all time

During the American Civil War countless treasures said to be worth millions of dollars were stolen and remain lost today. One of the culprits, Confederate ranger John Singleton Mosby and his men, launched an audacious night raid on the Fairfax County Courthouse, Virginia in 1863. Searching the building, they came across a sack thought to have contained gold, silver and jewels belonging to Fairfax County's most prominent families worth $6 million (£4.7m) in today's money.

The two treasure enthusiasts, Kevin Dykstra and Frederick J. Monroe, based their search on the deathbed confession of a local lighthouse keeper from 1921, who claimed that the bullions had been packed onto a train boxcar and smuggled north towards Lake Michigan. There it was loaded on a ferry but thrown overboard for a mysterious reason. Dykstra and Monroe thought that they may have found one of the gold bars, but so far their trove hasn't been confirmed and the hunt continues.

On 10 May 1881, a stagecoach loaded with silver and gold bars and coins worth over $3 million (£2.3m) in today's money was looted in the mountains near Flagstaff, Arizona. Legend has it that the group of thieves was tipped off by a crooked insider of the Wells Fargo bank, which was transporting the valuables to a branch in San Francisco. With local sheriffs and army cavalry in hot pursuit, the bandits were tracked to a remote cabin in the mountains, where a frenzied shootout followed.

The only egg recovered, the Third Imperial Egg, surfaced in 2012 at a scrap metal dealership in the American Midwest of all places. Still lost are the 1888 Cherub with Chariot, the Nécessaire from 1889 and the 1903 Royal Danish (pictured), among others, each of which is worth up to $30 million (£23.4m).

Read the incredible story behind the world's most luxurious eggs

Described as the "most stolen artwork of all time", Hubert and Jan van Eyck's 15th-century altarpiece Adoration of the Mystic Lamb has disappeared several times over the centuries. First it was nearly burned by Calvinists, then robbed by Napoleon, and stolen during the First World War. One of its 12 panels, which depicts the so-called Just Judges, was taken from the Saint Bavo Cathedral in Ghent, Belgium in April 1934 and is still missing today.

The remaining 11 panels, stolen again during World War II, have returned to the cathedral (pictured) and are now protected by a €30 million ($37m/£26m) bulletproof glass case, but the whereabouts of the 12th panel remains a mystery. Authorities decided not to pay a ransom demand for one million Belgian francs, and the suspected thief refused to reveal where he had hidden the artwork when he confessed to the heist on his deathbed. Most recently, experts believed they had found the location of the stolen piece – below a major square in Ghent – but investigators have been reluctant to dig up the paving stones. Should they change their minds, the artwork could finally be complete again.

Deemed "degenerate" by the Nazis, En Canot by Jean Metzinger (pictured) was confiscated by the Third Reich and put on display in the Degenerate Art Exhibition in Munich in 1936. Hitler abhorred modern artworks such as the Cubist painting and had many of them destroyed or sold on.

Metzinger's Cubist artwork, which represents an elegantly-dressed woman holding an umbrella while she sits in a small boat, caused a sensation when it was first exhibited in Paris in 1913, and was later acquired by Berlin's National Gallery. After it was shown in Munich, the Degenerate Art Exhibition was also displayed in other cities. That's when En Canot disappeared.

Among them was this painting depicting the daughter of Jewish collector Jenny Steiner, who fled Austria in 1938 just after the Nazis invaded Vienna. The portrait was seized by the troops, ostensibly in lieu of tax payments, though it is unlikely the Steiners owed anything. The last time the artwork was publicly seen was in 1941, when it was sold at auction to an unknown bidder.

This Renaissance masterpiece is widely regarded as the most important painting missing since World War II. Raphael's 1513-14 Portrait of a Young Man was taken by the Nazis from the Czartoryski Museum in Krakow, Poland in 1939. The Third Reich plundered an estimated 20% of European art during World War II, much of which is still missing today.

Worth $303 million (£235.2m), the splendid Amber Room is one of the most valuable treasures the Nazis plundered during the Second World War. Made of exquisite amber panels backed with gold leaf and ornate mirrors, it was the star attraction of the Catherine Palace in St Petersburg, Russia from the early 18th century until it was removed and stolen in 1941. The room was taken to Königsberg Castle in Kaliningrad, then part of Prussia, which was destroyed in 1945.

Another artwork robbed by the Nazis, An Angel with Titus’ Features by Rembrandt, which depicts the Dutch master's son, was kept in a chateau in the French countryside. During the German invasion in 1943 the Nazis took it with them to Paris, where it was set aside to be installed in Hitler's Führermuseum.

Over the decades, several artworks stolen by the Nazis during the Second World War have been recovered, or returned to descendants. This painting by Early Renaissance master Sandro Botticelli, however, is still waiting to be found. The priceless portrait is another piece that features on the Monuments Men Foundation's most wanted list and it was the most treasured object in the Filangieri Museum in Naples, Italy, until Hitler's troops got their hands on it.

On 30 September 1943, the Nazis discovered the painting in Villa San Paolo di Belsito in Naples, where it was being hidden, and decided to take it to Germany. En route it vanished and was never seen again.

Dating from around 1489, the Head of a Faun was the first known sculpture of great Renaissance master Michelangelo. The painter of the world-famous ceiling of the Sistine Chapel crafted the marble artwork when he was only 15 or 16, it is believed, winning him the patronage of the powerful Florentine leader Lorenzo de' Medici.

Until 1944 the priceless sculpture was displayed in the Bargello Museum (pictured) in Florence, Italy. In August that year, however, the Nazis looted the Michelangelo and loaded it onto a truck along with other treasures. Some experts have suggested the sculpture may have eventually found its way to the Soviet Union, but to this day it remains lost.

This self-portrait by Dutch master Vincent Van Gogh, which was painted in 1888, hasn't been seen since 1945. It is widely believed to have been destroyed in an air raid on Germany in the Second World War. However, there might still be hope. There are sources indicating the oil painting survived the blaze. 

In 1948 the opulent piece of jewellery mysteriously disappeared from the royal treasury of Patiala. Decades later, in 1982, the De Beers diamond reappeared at auction in Geneva, Switzerland. Another 16 years later a Cartier representative stumbled upon the platinum chains of the necklace in a second-hand jewellery store in London but with the biggest diamonds and the rubies gone. While Cartier was able to recreate the necklace, the whereabouts of the original gemstones are still a mystery.

For more than three centuries this 1609 painting by Italian Baroque master Caravaggio hung above the altar of the Oratory of San Lorenzo in Palermo, Italy. But on a stormy night in October 1969 the Nativity with St. Francis and St. Lawrence, which has been valued at $20 million (£15.5m), was cut out of its frame, allegedly by the Sicilian Mafia, and went missing.

One of the FBI's most wanted stolen artworks, the painting still hasn't been recovered. In 2015 a replica was commissioned to fill the empty frame in the church (pictured), while detectives continue to try to track down the valuable original. Most recently the Guardian revealed that the Mafia sliced off a piece of the painting's canvas to convince the Catholic Church to make a deal for its return, according to the testimony of a priest. The Mafia is also said to have been in touch with an art dealer in Switzerland, which police are currently investigating.

After the second theft 11 culture ministry employees were found guilty of negligence of their duties and sentenced to jail but freed on bail. Egyptian billionaire Naguib Sawiris (pictured) has offered a reward of $175,000 (£137k) for information leading to its recovery, which he hopes will lead to witnesses to coming forward.

Over to Sweden, where the theft of George Braque’s La nappe blanche (or Still Life) from Modern Museum in Sweden in 1993 has left authorities perplexed to this day as to its whereabouts. The 1928 painting was one in a haul of artwork stolen that night, which had a total value of $52 million (£40.1m) and included works by Picasso.

The so-called “Indiana Jones of the artworld” Arthur Brand (pictured) has teamed up with journalist Arvid Hallberg to find the painting. Brand was responsible for recovering Picasso’s Dora Maar, which was stolen along with La nappe blanche nearly 30 years ago. The art-sleuthing pair suspect the Braque is currently “in the possession of a northern European” somewhere in Spain…

Worth a whopping $200 million (£156m), Johannes Vermeer's The Concert is thought to be the most valuable stolen object ever. The painting was cut from its frame, alongside Rembrandt's The Storm on the Sea of Galilee and 10 other important works of art, at the Isabella Stewart Gardner Museum in Boston in March 1990.

While the world celebrated the new millennium with fireworks, a thief broke into the Ashmolean Museum in Oxford, England, and stole the View of Auvers-sur-Oise by Paul Cézanne. The landscape painting, which is valued at $3.9 million (£3m), has not been found.

The burglar was a professional. Detectives reported that he cut a hole in the roof of the Ashmolean Museum (pictured), under the cover of the noise of the midnight fireworks, and descended into the art gallery by rope ladder. He then created a smokescreen with a canister and fan to foil security cameras and escaped with the painting the way he came in. The robbery took just 10 minutes. A few weeks after the heist, investigators thought they had found the artwork in a Central England pub but it turned out to be a copy. 

Dubbed by police as "art heist of the century", Le Pigeon aux Petits-Pois by Pablo Picasso was stolen from the Musée d'Art Moderne de la Ville de Paris alongside four other paintings, including a Matisse and another Braque, altogether worth $123 million (£95m). 

The canvases were discovered missing from the museum when it opened its doors in May 2010. When the culprit was arrested in 2011, he stated he threw the artworks in a rubbish container after panicking. Police doubt that assertion, however, not giving up hope that the valuable paintings might still be out there somewhere. 

In the early hours of 27 March 2017 a giant Canadian gold coin called the "Big Maple Leaf", worth $4 million (£3.1m), disappeared from the Bode Museum in Berlin, Germany. And it was quite a heist: three thieves broke in through a window, wheeled the 220-pound coin, which is about the size of a car tyre, through the museum on a roller board, then used a rope and wheelbarrow to transport it across rail tracks and through a park to a getaway car.

A few months after the heist German police arrested three men from a family linked to organised crime, along with one employee of the museum who allegedly advised the thieves about safety measures. While the suspects have recently been on trial in Berlin (pictured), there's evidence the rare coin might have disappeared forever. Investigators found gold dust on clothing and a car of the suspected robbers, indicating they may have melted the treasure down. 

From the Elgin Marbles to the Rosetta Stones: stolen treasures countries want back

Here's arguably 2019's most headline-grabbing theft, a solid gold working toilet, created by Italian artist Maurizio Cattelan for an installation called America, which was taken by thieves from England's Blenheim Palace in September just days after it had been unveiled to the public. At first some suspected the theft was an elaborate prank concocted by the artist who is famous for his crazy stunts. A reward of £100k ($129k) has been put up for the toilet's safe return.

Despite seven people being arrested – all of whom have been released under investigation – the toilet has still not been recovered. As the toilet was plumbed in and fully working, the robbery also caused a significant amount of flooding and damage to the stately home.

On the night of Saturday 14 March 2020, a painting by renowned artist Anthony Van Dyck was stolen from the Christ Church Picture Gallery at Oxford University, England. A Soldier on Horseback, painted in 1616 and valued at $1.2 million (£1m), was stolen along with A Boy Drinking, Annibale Carraci's painting from 1580 and Salvator Rosa's A Rocky Coast, with Soldiers Studying a Plan, from the 1640s.

Police responded by saying that a “thorough investigation” was underway to find the artworks, with the gallery closing until further notice. They said there would also be an increased police presence in the area and urged any witnesses to get in touch.

March 2020 was a popular month for art theft, as less than two weeks after the Van Dyck went missing, a Van Gogh vanished from the walls of the Singer Laren Museum in the Netherlands. Parsonage Garden at Nuenen in Spring was taken on 30 March – Van Gogh’s birthday – after thieves smashed their way through the glass door to the gallery in the early hours of the morning and vanished by the time police arrived on the scene.

Parsonage Garden at Nuenen in Spring has an estimated value of €6 million ($7m/£5.5m) and was on loan from the Groninger Museum when it was taken. A full police investigation is still under way to find the painting, while art detective Arthur Brand has the valuable artwork high up on his “to-find” list. 

In the early hours of Thursday 27 August last year, police rushed to the Hofje van Mevrouw van Aerden museum in Leerdam, Netherlands after being alerted to the theft of a painting by a Dutch Master. Frans Hals' Two Laughing Boys, which depicts two young men laughing with a mug of beer, had previously been stolen from the same museum in 1988 and 2011. After the first theft in 1988, it took three years to track down the painting, while it took six months to find after the second theft. 

Estimated to be worth €15 million ($18m/£12.7m) according to an art expert who spoke to Dutch broadcaster RTL Nieuws, the painting, dating back to 1626, is thought to have been pilfered by thieves who broke in through the back door of the small museum. Police used CCTV and appealed to the public for information, but the investigation is ongoing.

The thieves are yet to be found, but are thought to have entered Arundel Castle (pictured) through a window and smashed a glass cabinet in order to take the treasures. An abandoned vehicle that had been set alight in the nearby town of Barlavington, about 20 minutes' drive away, has been identified by local police as "linked" to the crime.

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