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)

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 glass skywalk in Wanyuan, Sichuan province, built along the side of a cliff, is the highest such skywalk anywhere in China on January 31, 2017. Some visitors have been proven to be terrified by the experience had to brace against the wall in fear. (Photo by Chinanew.com/AsiaWire)

Rian Johnson, left, director of the upcoming film “Knives Out”, takes a picture of cast member Ana de Armas as they are introduced onstage during the Lionsgate presentation at CinemaCon 2019, the official convention of the National Association of Theatre Owners (NATO) at Caesars Palace, Thursday, April 4, 2019, in Las Vegas. (Photo by Chris Pizzello/Invision/AP Photo)

Flames rage through a pile of tires at the tire dump of Sesena in Toledo, Spain, 13 May 2016. The tire dump reportedly contains over 100,000 tons of tires and reaches to the neighbouring town of Valdemoro in Madrid. According to local authorities, the fire was apparently deliberately started as it had been raining till midnight and the fire started early 13 May 2016 at a small spot in Valdemoro. (Photo by Ismael Herrero/EPA)

Zhang Shifan's sixth-generation facekinis in Shandong Province, Qingdao, East China. A woman credited with inventing the bizarre swimwear known as the “facekini” has now proudly presented the sixth generation of the iconic beach clothing. The new facekini models are not only more comfortable, they also come in a wider variety of colours and patterns, bringing both style and practicality to beach-goers in Qingdao City, in East China's Shandong Province, who fear tan lines. (Photo by CEN)

Revelers throw colored corn starch into the air as they celebrate the 2015 Holi (Festival of Colors) at the Krishna Temple in Spanish Fork, Utah on Saturday, March 28, 2015. (Photo by Rick Bowmer/AP Photo)

Anna Malova, Miss Russia 1998, poses on a pool table at The Campbell Apartment restaurant in Grand Central Station on November 18, 1999. She makes her motion picture debut in the movie “Above Ground”. (Photo by Richard Corkery/NY Daily News Archive via Getty Images)