A single object, a single shape, a single colour,' is how Anish Kapoor summed up Leviathan, his response to the Monumenta challenge this year. Radically departing from Christian Boltanski’s busy collage-like approach in Personnes for Monumenta 2010, Kapoor has filled the 13,500 square metre space with a single cavernous entity which surges through the Grand Palais roof.

These powerful images capture the spear-wielding tribes of Papua new Guinea who believe they are possessed with the spirit of the crocodile. They show how the Kangunaman clansmen scar their backs to resemble reptile scales while the Huli Wigmen wear elaborate headdresses to signal they are ready for battle. (Photo by Trevor Cole/Media Drum World)

These images show the unique bond a group of free divers formed with gigantic sperm whales. Swimming just inches away from the huge mammals, the divers are dwarfed in size, made to look like specks in comparison. The photos were taken by renowned underwater photographers Alexandre Roubaud and Alexandre Voyer, who are based in Paris but travel the world to capture such stunning imagery. Here: a diver with a sperm whales. (Photo by Alexandre Roubaud/Alexandre Voyer/Caters News)

A Femen activist is led away by French police in Henin-beaumont, northern France, Sunday, May 7, 2017. Voters across France are choosing a new president in an unusually tense and important election that could decide Europe's future, making a stark choice between pro-business progressive candidate Emmanuel Macron and far-right populist Marine Le Pen. (Photo by Francois Mori/AP Photo)

A Nepalese Hindu devotee takes a holy bath as they mark the Mother's Day Festival at Matathirtha on the outskirts of Kathmandu on May 6, 2016. Nepalese Hindu devotees come from across the country to bathe, offer prayers and leave offerings at the Matathirtha Temple during the event, which honours mothers who have passed away. (Photo by Prakash Mathema/AFP Photo)

Tong Jieping, 44-year-old mentally disabled patient, is chained by his foot inside his room, in Qunxing village of Wangjiang county, Anhui province, China, July 14, 2015. Tong was diagnosed mentally ill when he was in his 20s. His parents, both in their 70s, could not afford the medical treatments so they had to lock him up in chains to prevent him from running away, according to Tong's family. (Photo by Reuters/Stringer)

Thoughts. They fly through the broad expenses of our mind, floating gracefully in midair, going into the clouds, and then reemerging once again. Some are quick and furtive, others are grand and majestic. We reflect upon them as they enter our minds, and once they leave, they are usually gone for good. However, some thoughts are different. These thoughts resemble a flock of angry birds or a swarm of hungry moths that invade your mind, slowly eating away at your sanity, strength, and desire to live. Such thoughts often plague that minds of people with Obsessive Compulsive disorder. They completely occupy their time; constantly there; ever-present. With his book sculpture, Thomas Wightman was able to accurately convey the way these thoughts consume the mind, slowly building a nest within it, resisting all attempts to drive them away.

A woman falls while slipping on ice during freezing rain on Roosevelt Island, a borough of Manhattan, in New York January 5, 2014. New York City was hit on Friday by the first severe winter storm of 2014 and was still in the grip of sub-freezing weather on Sunday morning. The woman got up and walked away from the fall. (Photo by Zoran Milich/Reuters)