A student from the General Yermolov Cadet School takes part in weapons training during a two-day field exercise near the village of Sengileyevskoye, just outside the south Russian city of Stavropol April 13, 2014. The General Yermolov Cadet School in the southern Russian city of Stavropol is a state-run institution that teaches military and patriotic classes in addition to a normal syllabus. (Photo by Eduard Korniyenko/Reuters)

Visitors check photos on a smartphone during the activity "Birgu by Candlelight" in the medieval city of Birgu, also known as Vittoriosa, outside Valletta, Malta, October 10, 2015. During the annual event, most street lights are switched off and the city is lit up by candlelight, creating a magical ambience, according to its local council. (Photo by Darrin Zammit Lupi/Reuters)

“Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London with 1,074,300 residents (2011 census), an increase of 96,000 over the previous decade. The city lies within the West Midlands conurbation, the third most populous urban area in the United Kingdom with a population of 2,440,986 (2011 census) of which the Birmingham built-up area was 1,085,810. Its metropolitan area is the United Kingdom's second most populous with 3,683,000 residents”. – Wikipedia. (Photo by Adrian Saker)

Inmates are seen at the transgender gallery in La Joya prison on the outskirts of Panama City, Panama February 3, 2016. Inmates of La Joya prison on the outskirts of Panama City are housed in makeshift cells amid heavy overcrowding, living in grimy conditions and with limited medical attention. Many prisoners in the Central American nation languish for years without being sentenced. (Photo by Carlos Jasso/Reuters)

A municipal worker sits on a bench, next to a statue, in Nizhny Novgorod, Russia, during the 2018 soccer World Cup, Thursday, June 28, 2018. Nizhny Novgorod was a “closed city” during the Soviet era. It was known as Gorky until 1990 and it was here that dissident scientist Andrei Sakharov was held under house arrest. Now the city hosts six World Cup matches and is teeming with tourists. That was unthinkable in the Soviet era and even rare now in a city that is seldom visited by outsiders. (Photo by Vadim Ghirda/AP Photo)

Stunning silhouettes under European cities reveal the size and splendor of the continent’s urban foundations. Photographer and content-manager Anna Arinova, 28, from Moscow, captured the awe-inspiring labyrinths in Russia and Germany. Here: Regenwurmlager, Poland. The Regenwurmlager is an extensive underground fortification area constructed by Germany in 1920s-1940s, now in western Poland, near the city of Międzyrzecz. (Photo by Anna Arinova/Caters News)

Tip turkey, dumpster chook, rubbish raptor – the Australian white ibis goes by many unflattering names. But it is a true urban success story, scavenging to survive in cities across Australia as wetlands have been lost. Wildlife photographer Rick Stevens captured them in Sydney. Here: Of all the species affected by river regulation in Australia, the ibis is one of the few that has changed its behaviour and moved to coastal cities. (Photo by Rick Stevens/The Guardian)

A man dressed as Hindu goddess Kali, the goddess of power, performs with a burning camphor tablet on his tongue during a religious procession ahead of the “Kumbh Mela”, or Pitcher Festival, in the northern Indian city of Allahabad January 6, 2013. During the festival, hundreds of thousands of Hindus take part in a religious gathering at the banks of the river Ganges. The festival is held every 12 years in different Indian cities. (Photo by Jitendra Prakash/Reuters)