Women are covered in dust after making it out of a building that collapsed after an earthquake in the Roma neighborhood of Mexico City, Tuesday, September 19, 2017. A powerful earthquake shook Mexico City on Tuesday, causing panic among the megalopolis' 20 million inhabitants on the 32nd anniversary of a devastating 1985 quake. The US Geological Survey put the quake's magnitude at 7.1 while Mexico's Seismological Institute said it measured 6.8 on its scale. The institute said the quake's epicenter was seven kilometers west of Chiautla de Tapia, in the neighboring state of Puebla. (Photo by Rebecca Blackwell/AP Photo)

A man wearing a Pikachu hat, a character from Pokemon, plays Pokemon Go during a gathering to celebrate “Pokemon Day” in Mexico City, Mexico August 21, 2016. (Photo by Carlos Jasso/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)

A passenger takes off his pants as others not wearing pants dance while waiting for a subway train during the “No Pants Subway Ride” in Mexico City, Mexico, February 21, 2016. The event is an annual flash mob and occurs in different cities around the world, according to its organisers. (Photo by Carlos Jasso/Reuters)

Runners sleep before competing in the 2016 New York City Marathon in the Manhattan borough of New York City, NY, U.S. November 6, 2016. (Photo by Eduardo Munoz/Reuters)

Workers carve ice art works at Harbin Ice and Snow World one day before the 32th Harbin International Ice and Snow Festival in Harbin city, China's northern Heilongjiang province, 04 January 2016. The festival will run from 05 January to 05 February. (Photo by Wu Hong/EPA)