“A Double Eagle is a gold coin of the United States with a denomination of $20. (Its gold content of 0.9675 troy oz was worth $20 at the then official price of $20.67/oz). The coins are made from a 90% gold (0.900 fine = 21.6 kt) and 10% copper alloy”. – Wikipedia

Photo: A “Double Eagle” gold twenty dollar coin is displayed above a catalogue picture showing the reverse side of the coin at Goldsmith's Hall on March 2, 2012 in London, England. Nearly half a million of these coins were originally minted in the midst of the Great Depression in the US. Only 13 are known today after the rest were melted down before they ever left the US Mint, sacrificed as part of a strategy to stabalise the American economy. In 2002 a Double Eagle sold at auction for $7.6 million. (Photo by Peter Macdiarmid/Getty Images)

Local villagers ride a local coal powered steam train on March 27, 2015 at a station in the town of Shixi , Sichuan Province, in Southern China. While China boasts the world's most extensive high-speed rail infrastructure with over 16,000 kilometers of track, the Shixi-Bagou railway is still a primary connection for local villagers between towns and is kept alive by tourist cars carrying passengers for ten times the price. The rail line came into service in the late 1950s and the train was initially used to transport coal from a now-shuttered mine before passenger carriages were added. (Photo by Kevin Frayer/Getty Images)

This picture taken on March 16, 2017 shows a crew member introducing the dining car of the Train Suite Shiki- Shima, operated by East Japan Railway, in Tokyo during a press preview. The luxury sleeper Shiki- Shima, which can accommodate up to 34 passengers, has 10 cars, including a lounge car, a dining car and two observatory cars. The train has only 17 cabins, all suites, and the most expensive room, known as Shiki- Shima Suite, is priced at 950,000 yen (8480 USD) per person when shared by two people. (Photo by AFP Photo/JIJI Press)

Members of the Mahogany Blue Baby Dolls including Victoria “Lady Lotus” Spotts (C) march in the 25th Anniversary Satchmo Salute second line parade, honoring New Orleans jazz legend Louis Armstrong, on August 3, 2025 in New Orleans, Louisiana. Revelers marched from historic St. Augustine Catholic Church in the Tremé neighborhood to the New Orleans Jazz Museum where Satchmo Summerfest is being held. (Photo by Mario Tama/Getty Images)

Jeremy Davis (L) demonstrates the operation of the safe room shelter door lock to homeowner Rob Hamlin on June 18, 2011 in Neosho, Missouri. Once thought of as a luxury item there has been a surge of interest from homeowners in purchasing shelters to ride out damaging storms ever since a F5 tornado tore through the town of Joplin, Missouri. Ranging in price from $3,000 to $5,000 homeowners can supplement the cost with a mortgage insurance program offered by the U.S. Department of Housing and Urban Development for installing a safe room built to FEMA specifications. Lawmakers in Alabama have even considered requiring construction of storm shelters in mobile home parks after forty people died in April. (Photo by Julie Denesha/Getty Images)

A tunnel with electric switches are seen in Josip Broz Tito's underground secret bunker (ARK) in Konjic, October 16, 2014. In the early 1950s, Josip Broz Tito, the late leader of the former Yugoslavia, ordered the building of the secret bunker, located 900 feet (270 m) underground and near the Bosnian town of Konjic, to safeguard the country's ruling class in case of a nuclear attack. Construction at the complex, which had a cost equivalent price tag of $4.6 billion, continued until 1979, the year before Tito died. (Photo by Dado Ruvic/Reuters)

The National Geographic Photo Ark is a travelling exhibition of photographer Joel Sartore’s quest to create a photo archive of biodiversity around the world. So far, Sartore has captured studio portraits of more than 6,000 species – a number that he hopes to double. On 1 July, the ark will open at Melbourne zoo – the first time it has been exhibited in the southern hemisphere. More than 50 portraits will be on display, including many of Australian endangered animals being protected by programs at the zoo itself. These captions have been edited from text supplied by Melbourne zoo. Here: Barking owl. (Photo by Joel Sartore/National Geographic Photo Ark/The Guardian)

Opposites can attract and Anzac a doe-eyed baby kangaroo has become best friends with Peggy, a tiny squint-eyed wombat. Their unlikely union developed after the pair - both orphans - shared a pouch at the Wildlife Kilmore Rescue Centre in Victoria, Australia. At just over five months old, Anzac was brought to the centre after being rescued in the Macedon Ranges. The joey is in the mother kangaroo's pouch for about eight months, depending on the species, but Anzac was abandoned a few months before he was ready to be free.