The Ivanpah Solar Electric Generating System is seen in an aerial view on February 20, 2014 in the Mojave Desert in California near Primm, Nevada. The largest solar thermal power-tower system in the world, owned by NRG Energy, Google and BrightSource Energy, opened last week in the Ivanpah Dry Lake and uses 347,000 computer-controlled mirrors to focus sunlight onto boilers on top of three 459-foot towers, where water is heated to produce steam to power turbines providing power to more than 140,000 California homes. (Photo by Ethan Miller/Getty Images)

Dunnottar Castleis a ruined medieval fortress located upon a rocky headland on the north-east coast of Scotland, about 3 kilometres (1.9 mi) south of Stonehaven. The surviving buildings are largely of the 15th and 16th centuries, but the site is believed to have been fortified in the Early Middle Ages. Dunnottar has played a prominent role in the history of Scotland through to the 18th-century Jacobite risings because of its strategic location and the strength of its situation. Dunnottar is best known as the place where the Honours of Scotland, the Scottish crown jewels, were hidden from Oliver Cromwell's invading army in the 17th century. The property of the Keiths from the 14th century, and the seat of the Earl Marischal, Dunnottar declined after the last Earl forfeited his titles by taking part in the Jacobite rebellion of 1715. The castle was restored in the 20th century and is now open to the public.

A British photographer has captured life at the “edge of the world”. Timothy Allen, best known for his work on BBC's Human Planet, trekked through the freezing Siberian wilderness for 16 days as he joined part of an 800km migration of reindeer in the Yamal-Nenets region – a name that roughly translates to “edge of the world”. The stunning pictures feature the nomadic Nenets tribe, who drink blood to survive in -45°C temperatures. Timothy's epic journey, which will be revealed in an eight-minute documentary on Animal Planet USA, saw him travel across the bleak terrain of the frozen Ob River with the Nenets people in December last year. Here: An empty camp is shown beneath a colourful sky in Siberia, December 2016. (Photo by Timothy Allen/Barcroft Productions)

A man reacts after catching a trout with his hands during an event promoting the Ice Festival on a frozen river in Hwacheon, about 20 km (12 miles) south of the demilitarized zone separating the two Koreas, January 10, 2015. The annual ice festival, which is one of the most famous and biggest festivals in South Korea, expects to see more than 1,000,000 people attend. The festival lasts for three weeks from January 10 this year. (Photo by Kim Hong-Ji/Reuters)

French twins Thomas and Vincent (L) Seris take the tram in Bordeaux, November 12, 2014. Born with Xeroderma Pigmentosum (XP), the twins cannot be exposed to the sun and its ultraviolet (UV) light, which could provoke precocious cancers due to an autosomal recessive genetic disorder of DNA repair. Colloquially referred to as Children of the Night (Les Enfants de la Lune) the Seris twins are among 70 to 80 people in France who suffer from the genetic defect. The French association “Les Enfants de la Lune” reports that there are between five and ten thousand such cases in the world. Thomas and Vincent have been testing a new protective mask for the last year which is transparent and ventilated and developed by several hospitals in France. (Photo by Regis Duvignau/Reuters)

South Korean traditional bow artisan Kwon Yeong-Hak works on a bow in his workshop in Yecheon-gun, Gyeongsangbuk-do, South Korea, 26 February 2015. Kwon Yeong-Hak still crafts his bows in the traditional way, carrying on a four-generation family business. The Gakgung bow, of which Kwon is one of the last remaining artisans, is unique to Korea, and is constructed with a variety of materials, including water buffalo horn, oak, bamboo and cattle spinal sinew. A ban on the import of water buffalo horns has put the Gakgung tradition at risk. (Photo by Jeon Heon-Kyun/EPA)

A Uyghur boy sits atop a horse as he has his picture taken outside the Id Kah Mosque before the Eid holiday on July 28, 2014 in old Kashgar, Xinjiang Province, China. Nearly 100 people have been killed in unrest in the restive Xinjiang Province in the last week in what authorities say is terrorism but advocacy groups claim is a result of a government crackdown to silence opposition to its policies. China's Muslim Uyghur ethnic group faces cultural and religious restrictions by the Chinese government. Beijing says it is investing heavily in the Xinjiang region but Uyghurs are increasingly dissatisfied with the influx of Han Chinese and uneven economic development. (Photo by Kevin Frayer/Getty Images)

“At her job, Maria Torero cares for sick human beings. At home, she lavishes love on slowly dying cats – 175 of them at last count. The 45-year-old nurse has turned her two-story, eight-room apartment into a hospice for cats with feline leukemia, scattering it with scores of feeding dishes and at least two dozen boxes litter boxes. Some have suggested she shelter healthy cats instead. “That's not my role”, she told The Associated Press. “I'm a nurse. My duty is to the cats that nobody cares about”. She said that “people don't adopt adult cats, especially if they are terminally ill”. – Franklin Briceno via Associated Press. (Photo by Martin Mejia/AP Photo)