Enjoying a tickle from her keeper, an orphaned orangutan at the SOCP Quarantine Centre in Sumatra, Indonesia on March 20, 2016. The island’s orangutan population has been devastated in recent years as the forest areas are destroyed to make way for palm oil plantations. (Photo by Jami Tarris/Barcroft Media)

Behaviour: Mammals category. Giant Gathering by Tony Wu, USA. Dozens of sperm whales mingled noisily off Sri Lanka’s northeast coast, stacked as far down as Tony could see. This was a congregation of dozens of social units, like a gathering of the clans. Aggregations like this could be a critical part of the whales’ rich social lives but are rarely reported. Some two thirds of the population was wiped out before commercial whaling was banned in 1986. This kind of major gathering could be “a sign that populations are recovering”, says Tony. (Photo by Tony Wu/Wildlife Photographer of the Year 2017)

Nyibol Lual, 13 years old, helps her family to prepare the land for cultivation on May 31, 2017, in Panthau, Northern Bahr al Ghazal, South Sudan. The family has a small land where they cultivate sorghum. An estimated 63 per cent of the population in Northern Bahr al Ghazal is experiencing severe food insecurity, according to the latest Integrated Food Security Phase Classification (IPC) report. The situation is particularly bad in Aweil West and Aweil South counties, where the exhaustion of household food stocks and growing dependence on financially inaccessible markets have left the population facing Emergency levels of food insecurity. (Photo by Albert Gonzalez Farran/AFP Photo)

Bomarzo's main attraction is a garden, usually referred to as the Bosco Sacro (Sacred grove) or, locally, Bosco dei Mostri ("Monsters' Grove"), named after the many larger-than-life sculptures, some sculpted in the bedrock, which populate this predominantly barren landscape.

Li Guoqiang talks on his phone outside his house at Guangfuli neighbourhood, in Shanghai, China, April 1, 2016. Li, 38, is a deliveryman who rents a place at Guangfuli. In a corner of Shanghai, surrounded by a cement wall, lies one of the world's most valuable fields of debris and garbage. On paper, the Guangfuli neighbourhood is a real estate investor's dream: a plot in the middle of one of the world's most expensive and fast-rising property markets. But the reality is more like a developer's nightmare, thanks to hundreds of people living there who have refused to budge from their ramshackle homes for nearly 16 years as the local authority sought to clear the land for new construction. (Photo by Aly Song/Reuters)

A soldier stands guard on the aircraft park of the Pyongyang Airport on April 3, 2011 in Pyongyang, North Korea. Pyongyang is the capital city of North Korea and the population is about 2,500,000.

Indian commuters travel in a local train in Kolkata, India, Tuesday, February 26, 2013. Indian Railway Minister Pawan Kumar Bansal is presenting the country's rail budget for next fiscal year in the parliament Tuesday, Feb. 26, 2013. Indian railway network is one of the world's largest, with some 14 million passengers daily and some 64,000 kilometers (40,000 miles) of railway track cut through some of the most densely populated cities. (Photo by Bikas Das/AP Photo)

A view of the Tianducheng development in Hangzhou, Zhejiang Province August 1, 2013. Tianducheng, developed by Zhejiang Guangsha Co. Ltd., started constructing in 2007 and was known as a knockoff of Paris with a scaled-replica of the Eiffel Tower, standing 108 metres, and Parisian houses. Although designed to accommodate at least ten thousand people, Tianducheng remains sparsely populated and is now considered as a “ghost town”, according to local media. (Photo by Aly Song/Reuters)