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)

A baby giant panda plays at Chengdu Research Base of Giant Panda Breeding in Chengdu, Sichuan province, China, January 22, 2017. (Photo by Jason Lee/Reuters)

A female black lemur (Eulemur macaco), looks at a camera in its enclosure at Bioparc Fuengirola in Fuengirola, near Malaga, southern Spain, February 8, 2017. (Photo by Jon Nazca/Reuters)

A workman sweeping the highest sidewalk in the world, the 81st story of the Empire State Building, the world's tallest building, to the top of which the greatest dirigible “Los Angeles” will attempt to moor, New York, New York, early 1930s. This photo was made 1,248 feet above street level. (Photo by Adam Glickman/Underwood Archives/Getty Images)

A dog catches a frisbee during a dog frisbee competition in Moscow, September 13, 2015. Dogs and their owners took part in a variety of distance and accuracy tests during the competition to check their frisbee skills. (Photo by Sergei Karpukhin/Reuters)

Indonesian mahouts clean their Sumatran elephant in a river near the zoo in Medan, North Sumatra, Indonesia, 12 December 2014. According media reports, the smallest of the Asian elephants, Sumatran elephant (Elephas maximus sumatrensis) is facing serious pressures arising from illegal logging and associated habitat loss and fragmentation in Indonesia. The population has come under increasing threat from rapid forest conversion to plantations. (Photo by Dedi Sahputra/EPA)

Angora rabbit Emilson sits next to its freshly shaved hair at Georgia Spausta's small farm in Herzogbirbaum, Austria March 10, 2015. Spausta produces hand-spun yarn from some 25 angora rabbits which is sold in small scale to enthusiasts or at local markets. The rabbits are clipped four times a year, each time giving some 300 grams of wool, about the amount needed to knit one pullover. (Photo by Heinz-Peter Bader/Reuters)

Female of pygmy hippopotamus called Malaya from Netherlands in zoo in Dvur Kralove nad Labem, Czech Republic, February 22, 2016. (Photo by David Tanecek/CTK via ZUMA Press)