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 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)

The launch of a rocket into space is projected on Dubai's Burj Khalifa on February 9, 2021 as the UAE's “Al-Amal” – Arabic for “Hope” – probe's to Mars carries out a tricky manoeuvre to enter the Red Planet's orbit. A tense half-hour today will determine the fate of “Hope”. If successful, the probe which is designed to reveal the secrets of Martian weather, will become the first of three spacecraft to arrive at the Red Planet this month. (Photo by Giuseppe Cacace/AFP Photo)

Beautiful red sunset sky over Edinburgh, Scotland. Edinburgh is the capital city of Scotland and a popular tourist destination. It is also a major European financial (fund management) centre. Prominent buildings from left to right are: Edinburgh Castle, The Balmoral Hotel Clock Tower and The Scott Monument. (Photo by John Lawson/Getty Images)

A full moon is seen behind buildings at night in Ashkelon, southern Israel on December 1, 2020. (Photo by Amir Cohen/Reuters)

A brig with scarlet sails travels on the Finnish Gulf coast during a rehearsal for the the Scarlet Sails festivities marking school graduation in St. Petersburg, Russia, early Saturday, June 27, 2020. This year the festival will not be held in the city center, but on the Finnish Gulf. Due to the coronavirus pandemic, there will be no spectators but the event will be broadcast on television. (Photo by Dmitri Lovetsky/AP Photo)

People take photos with the skyline of the central business district in Singapore on September 10, 2015. (Photo by Edgar Su/Reuters)