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)

Employee of ornithological flight support service Nika Ryzhova-Alenicheva holds her hawk, which is used to control fauna to avoid bird strikes during takeoffs and landings, at Domodedovo airport outside Moscow, Russia September 2, 2016. (Photo by Maxim Zmeyev/Reuters)

Workers polish a snow sculpture ahead of the 16th Harbin Ice and Snow World in Harbin, Heilongjiang province, December 22, 2014. The 16th Harbin Ice and Snow World will be officially opened on January 5, 2015. (Photo by Reuters/Stringer)

Bulgarian men dance in the icy waters of the Tundzha river during a celebration to commemorate Epiphany Day in the town of Kalofer January 6, 2015. It is believed that the ritual will bring good health to the participants throughout the new year. (Photo by Stoyan Nenov/Reuters)

People line up to buy toilet paper and baby diapers at a supermarket in downtown Caracas January 19, 2015. There's a booming new profession in Venezuela: standing in line. The job usually involves starting before dawn, enduring long hours under the Caribbean sun, dodging or bribing police, and then selling a coveted spot at the front of huge shopping lines. As Venezuela's ailing economy spawns unprecedented shortages of basic goods, panic-buying and a rush to snap up subsidized food, demand is high and the pay is reasonable. (Photo by Jorge Silva/Reuters)

Damaged vehicles sit on Yeongjong Bridge in Incheon, South Korea, Wednesday, February 11, 2015. Two people were killed and at least 42 were injured on Wednesday after a pileup involving about 100 vehicles in foggy weather on the bridge near the Incheon International Airport, South Korean officials said. (Photo by Suh Myung-gon/AP Photo/Yonhap)

A woman dressed as a cleaning lady laughs during “Weiberfastnacht” (Women's Carnival) in Cologne February 12, 2015. Women's Carnival marks the start of a week of street festivals, the highlight of the event being “Rosenmontag” (Rose Monday), the final day of the carnival where mass processions are held. (Photo by Ina Fassbender/Reuters)

Baby clouded leopards, born early in March 2015, are presented by zoo keepers at the Olmense Zoo in Olmen, Belgium, April 16, 2015. The clouded leopard is an endangered species with only some 10,000 specimen remaining on earth, said Robby Van der Velden, a biologist at the Olmense Zoo. (Photo by Yves Herman/Reuters)