It’s not just precious metals such as gold that countries are keen to amass; a whole host of products from cheese to maple syrup have become quirky nest eggs for nations across the globe. While some collections have now been consigned to history, such as the European butter mountain, other unusual hoards are still being stashed away. We take a look at the weird and wonderful reserves that are worth a small fortune around the world.

North Americans have been tapping the sap from Maple trees and boiling it into the golden elixir that is maple syrup for hundreds of years. Over 70% of the world's maple syrup is produced in the French-speaking province of Quebec in eastern Canada. The Fédération des producteurs acéricole du Québec (FPAQ) is a cooperative marketing group run by the region's syrup producers that controls the supply and demand of maple syrup. And it has built up quite a syrupy stockpile.

In 2017, 152.2 million pounds of maple syrup was harvested by FPAQ members and dispensed into 308,000 barrels. This has an estimated worth of $318m (C$410m/£229m) in income for FPAQ members. To keep the price high, not all of this was released straight on to the market, however. And this stockpile is now heavily secured after thieves made off with 540,000 gallons of the syrup in 2012, roughly 12.5% of the reserve.

China is thought to be the largest producer and consumer of pork in the world and the Chinese government has often intervened to control the supply and price of its people's favorite food. Rising food prices have been known to trigger periods of civil unrest in the country, which is thought to be one of the reasons the Chinese government likes to control the supply of pork. China's national pork reserve was established in 2007.

The growing middle class has increased the demand for pork in China and as more people can afford to buy it the price has risen. In March 2016 it was reported that the price of pork in China had gone up nearly 30% year on year. In a bid to halt the price increases the government released 3.05 million kg of frozen pork onto the market over two months. Prices have now stabilized and there is now less demand for pork imports from China, which has impacted on global pork prices.

A record grain harvest in 2016 meant that many countries produced more wheat than they required. Russia recorded its second highest crop in its history, only beaten by its yield in 1978. Improved farming practices and technology have also helped boost Russia's wheat production and it's predicted the country could add 25 million metric tons of wheat to its yield over the next 10 years. The increase in Russia's grains stores is having a huge impact on the global economy.

Not all of Russia's excess wheat is being stored up for a rainy day. Russia was once largely reliant on foreign exports for its grain supplies, but now it has more grain than it knows what to do with at home it can offload it in Europe and America, undercutting local suppliers as it does so. In turn, this is leading to unwanted European grain being put into storage by farmers unwilling to sell at a price much lower than they desired.

In 2016, America produced more cheese than it could eat or sell, leading to huge caches of cheese stacking up in cold-storage facilities across the nation. By the end of March 2016 there was reportedly 1.19 billion lbs of cheese in America's largest stockpile ever. This surplus was partly a result of American cows producing more milk than predicted and required, with the excess being put into cheesemaking, but foreign forces had a hand in this too.

In a tit for tat over EU sanctions, Russia banned agricultural imports, including cheese, from the EU in 2014. This forced European producers to look for new markets for their cheese and with the falling Euro much of it ended up in America. In a bid to cut the cheese mountain, the US government stepped in, spending $20 million (£14.4m) on 11 million lbs of cheese in August 2016. This was given to food banks and those in need across the country. The cheese glut has been fixed for now.

Japan has built up quite a stockpile of plutonium. It is the only state that doesn’t make nuclear weapons from the spent commercial plutonium produced by its nuclear reactors. It means Japan has a lot of potentially weapons-usable plutonium in stock, prompting international calls for the country to rethink its nuclear reactor processing procedures as a result.

Japan did reportedly reduce its plutonium stores by one ton, as of the end of 2016, to about 46.9 tons. Of this, only about 9.8 tons are said to be stored within Japan. The remaining 37.1 tons is said to be held in Britain and France, where spent nuclear fuel from Japanese nuclear plants is sent for reprocessing. 

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As of May 2017, the National Fishermen's Association of Malaysia (Nekmat) reportedly had 50 tons of high-quality frozen fish, known as 'Q' fish, held in storage centers across the country. During times of hardship or high demand, such as Chinese New Year and Ramadan, when the price of fish is very high, Nekmat has released some of its frozen fish stocks at less than market price in a bid to stabilize pricing in the country.

Malaysians reportedly consume 53kg of fish per capita each year and are the highest consumers of fish in southeast Asia. Keeping a stockpile of frozen fish not only helps to control the price of fish in the country, it also ensures that there are supplies that the population can draw on during the inevitable low-catch seasons.

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In 1986, the European Union member states were said to be storing around 1.5 million tons of surplus butter, and were spending $1.3 billion (£935m) a year storing it. This excess was blamed on modern intensive farming practices increasing yields; rising prices in Europe, which shrunk the traditional export markets for butter abroad; and the Common Agricultural Policy, which gives protection to European farmers against foreign competition through levies on imports.

Nearly 30 years later, Europe's butter mountain is now little more than a puddle. In May 2017, the European Union was reported to have just 1,369 tons in its reserves, down from the 92,548 tons held just a year before. It is thought this fall is down to a reduction in milk production and a growth in butter consumption, with many people now seeing butter as healthier than vegetable oil margarine-type alternatives. Butter prices have risen as a result.

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In 2008 the Svalbard Global Seed Vault was built inside an abandoned arctic coal mine, deep within a mountain on a remote island in Norway's Svalbard archipelago. The vault was designed to hold the seeds of as many of the world's crops and plants as possible and it's been a success. In the event of a vast man-made or natural disaster people from all over the world could call on the vault to restore natural flora and fauna to their land.

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The seed bank, which was built to withstand any eventuality, didn't have quite what was needed to protect it against global warming. It was built underneath permafrost, but unusually high temperatures caused parts of this to melt and, while the water didn't get inside the seed bank itself, it penetrated the entrance. Norway has now set aside $13 million (£9.3m) to upgrade the facility to ensure its 890,000 seed samples stay out of harm's way.

The ice found in mountain glaciers can tell scientists a phenomenal amount about the world's climate and environment. It is thought that this ice can help to predict and perhaps even avert future environmental changes. As parts of these glaciers are melting, the Ice Memory program was developed to store ice cores from high-mountain glaciers most at risk from climate change. These are now stored in a snow cave in Antarctica.

Glaciers most at risk of global warming around the world are earmarked and a drilling mission extracts two or three full ice cores for storage. These cores are then carefully carried down the glacier in specially-insulated boxes and transported by ship to Antartica, where they enter the archive facility.

India is the world's largest cotton producer. In 2017/2018 it is forecast to produce 6.1 million tons of cotton, with 930,000 tons of this lined up for export. The government-run Cotton Corporation of India is designed to protect the interests of cotton farmers and to ensure they get a fair price for their cotton. As part of this mission it stockpiles cotton too. At one point in 2015 it was said to have held 6.5 million bales of cotton in its stores.

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The Cotton Corporation of India had to sell off a chunk of its surplus cotton bales in 2015. This was as a result of an unsustainable cotton surplus due to a bumper harvest and a fall in demand for cotton exports to China, where an expanding homegrown cotton industry has reduced the demand for foreign imports.

The Frozen Ark Project, based at the University of Nottingham in England, was originally set up to focus on the evolution of the biology of the land snail. However the research quickly turned into a study of extinction as the scientists discovered that about a hundred species of snails had died out in just 15 years. The project then rapidly expanded its remit and it became dedicated to collecting, preserving and storing the cells and DNA of all the world's endangered species.

Museums, researchers and zoos worldwide are now members of the Frozen Ark Project consortium. So far, over 700 DNA samples have been collected and stored in Nottingham in its -80°C (-112°F) freezers. These include samples from the scimitar horned oryx, which is extinct in the wild, and a variety of endangered species such as the Colombian spider monkey, pileated gibbon, siamang gibbon, lar gibbon, snow leopard and Malayan tapir.

Vietnam's Ministry of Agriculture and Rural Development said that the country was on target to produce 44.1 million tons of rice in 2017. It wasn't a bumper harvest year as adverse winter weather and disease reduced the yield. As Vietnam has now expanded its rice farming area, a greater yield is predicted for 2018. To protect the nation's staple food from unforeseen circumstances, Vietnam has a national rice reserve that can be dipped into in times of need.

From April 2016 to June 2017, 58,885 tons of rice, valued at $24.2 million (VN$553bn/£17.4m), were taken from the Vietnamese national reserves and distributed to people in need across the country. In December 2017, the Vietnamese government passed a resolution to allocate a further $24.2 million (VN$553bn/£17.4m) to refill the national rice reserves.

Thailand is the world's largest producer and exporter of natural rubber. Rubber farmers cut the bark of rubber trees and extract the milky substance known as Latex from it. This is then refined to produce rubber, used in thousands of everyday objects from car tires to gloves. As this material is so key to the Thai economy, the Thai government keeps state stockpiles of rubber in order to have some control over its supply and demand.

In January 2017, the Thai government announced it was selling 98,000 tons of rubber from its national reserves. This sale, worth around $211 million (6.64bn Thai baht/£152m), was designed to minimize the damage to the economy caused by recent flash floods in Thailand's main rubber-plantation region. The sale reportedly left 212,000 tons of rubber in state stockpiles, down from 310,000 tons.

In order to sustain the supply of tobacco for its world-famous Cuban cigars, Habanos, the Cuban company that produces and sells the cigars, has built up a stockpile of its precious tobacco leaves. This stockpile has been a useful safety net to fall back on when the tobacco crop was severely damaged by detrimental weather, pests or disease.

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In 2010, Cuba's tobacco harvest was cut right back in response to a fall in global demand for cigars. This was triggered by a global economic crisis and a reduction in tobacco smoking for health reasons. Instead of buying in fresh leaves, Habanos began drawing on its stockpile. In 2009, Cuba reportedly exported 73 million cigars, down from 217 million in 2006. New demand for cigars from China has helped Habanos to recover, however, raking in $500 million (£360m) in global sales in 2017.

Rhino horns attract a very high price on the black market, leading to poachers taking great risks to procure them. When rhinos die of natural causes in the wild their horns are immediately removed to ensure they're not snatched by poachers. As a result of there are said to be many secure rhino horn stockpiles across Africa, many of these stored horns come from natural rhino deaths, as well as horns obtained during botched poaching operations.

Those that manage rhino horn stockpiles have to adhere to a strict code of conduct and maintain detailed records of their stock, which must also be carefully stored to protect them from damage. This, together with the high security required, makes storing the horns very expensive. Some call for the horns to be destroyed, while others say they should be sold legally to help end the black market trade. Some scientists also say they should be kept for their research value.

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