Revellers watch as police officers dance in the street at the Notting Hill Carnival in west London, August 30, 2015. (Photo by Toby Melville/Reuters)

A model presents a creation during the Ashley Williams catwalk show at London Fashion Week in London, Britain February 14, 2020. (Photo by Henry Nicholls/Reuters)

A tree is silhouetted against a light display during the The Magical Lantern Festival marking the Chinese new year at Chiswick House in London, Britain January 18, 2017. (Photo by Neil Hall/Reuters)

To commemorate the centennial of Britain’s involvement in the First World War, ceramic artist Paul Cummins and stage designer Tom Piper conceived of a staggering installation of ceramic poppies planted in the famous dry moat around the Tower of London. Titled “Blood Swept Lands and Seas of Red,” the final work will consist of 888,246 red ceramic flowers—each representing a British or Colonial military fatality—that flow through grounds around the tower.

A participants mends his vintage car during the annual London to Brighton veteran car run in London, Britain November 6, 2016. Around 600 classic cars took part in the annual 60 mile journey to the south coast resort. (Photo by Neil Hall/Reuters)

A model prepares backstage of the House of Holland catwalk show during London Fashion Week Women's A/W19 in London, Britain on February 16, 2019. (Photo by Henry Nicholls/Reuters)

A clown checks her phone as she waits outside the Basilica of Our Lady of Guadalupe, in Mexico City, Monday, December 14, 2015. Hundreds of clowns belonging to various clown associations made their annual pilgrimage to the Basilica on Monday to pay their respects to the Virgin of Guadalupe, Mexico's patron saint. (Photo by Rebecca Blackwell/AP Photo)

A period of relative stability has put the Iranian capital No1 on the list of world cities that have achieved biggest improvements in liveability over the past five years, as calculated by the Economist Intelligence Unit. The “most improved” top 10 contains some unexpected names. So, eg, the fourth place: Abidjan, Ivory Coast. Latest ranking: 128; Ranking five years ago: 131; Five-year index movement: 3.8%. Here: A supporter of Ivory Coast president Alassane Ouattara campaigns in a market in the city’s Koumassi quarter. (Photo by Sia Kambou/AFP Photo)