A protester reacts as police use water cannon during a demonstration to demand changes in the Chilean education system in Santiago, Chile June 25, 2015. (Photo by Ueslei Marcelino/Reuters)
Demonstrators perform a dance in front of riot policemen during a march called by students to request changes in the education system in Santiago, Chile September 5, 2017. (Photo by Ivan Alvarado/Reuters)
Burmese children attend classes at a government run school December 14, 2011 in Waw township, Myanmar. The education system is based on the United Kingdom's system, after nearly a century of British and Christian presences in Burma. (Photo by Paula Bronstein/Getty Images)
An Israeli missile is launched from the Iron Dome missile system in response to a rocket launch from the nearby Palestinian Gaza Strip, on March 12, 2012 near Ashdod, Israel. (Photo by Uriel Sinai/Getty Images)
Penitentiary system guards carry an inmate with symptoms related to the novel coronavirus at the COVID-19 unit of San Juan de Dios hospital in Guatemala City on July 13, 2020. (Photo by Johan Ordonez/AFP Photo)
Children playing on Walled City rooftop in Hong Kong, 1989. The lack of formal governance in the Walled City led to challenges, but it also fostered a unique system of informal social order. (Photo by Greg Girard/The Guardian)
A simulated casualty is evacuated during an emergency services exercise at the disused Aldwych underground station on February 22, 2012 in London, England. Operation Forward Defensive aims to test the response to a terrorist incident on the London Underground network during the 2012 Olympic Games. (Photo by Peter Macdiarmid/Getty Images)
The Stockholm metro (Swedish: Stockholms tunnelbana) is a metro system in Stockholm, Sweden. The first line opened in 1950, and today the system has 100 stations in use, of which 47 are underground and 53 above ground. There are seven lines numbered from 10 to 19, in three groups identified by a color: the Green, Red and Blue lines. Each color line has two or three numbered lines on shared sections through the Stockholm City Centre.