A hot air ball balloon floats past while people stand in line to climb the Pyramid of the Sun and welcome the spring equinox in the pre-hispanic city of Teotihuacan, on the outskirts of Mexico City, Mexico, March 20, 2016. Spring equinox in Teotihuacán is an annual event which takes place around the 20th and 21st of March at the pre-Hispanic site of Teotihuacán, Mexico. This event is mirrored by other similar events in other pre-Hispanic sites such as Chichén Itzá and Malinalco, Mexico State. (Photo by Edgard Garrido/Reuters)

A student activist is detained during a silent protest after Thailand's election commission filed charges against a group for posting “foul and strong” comments online criticising a military-backed draft constitution, in Bangkok, Thailand April 27, 2016. (Photo by Jorge Silva/Reuters)

Covered in prayer shawls, Ultra-Orthodox Jewish men participate in a blessing during the holiday of Sukkot, in front of the Western Wall, the holiest site where Jews can pray in Jerusalem's Old City, Wednesday, September 30, 2015. The Cohanim, believed to be descendants of priests who served God in the Jewish Temple before it was destroyed, perform a blessing ceremony of the Jewish people three times a year during the festivals of Passover, Shavuot and Sukkot. (Photo by Oded Balilty/AP Photo)

Indian girls in traditional attire pose for photographs as they practice the Garba, the traditional dance of Gujarat state, ahead of Navratri festival in Ahmadabad, India, Saturday, October 3, 2015. Navratri or nine night festival will begin on October 13. (Photo by Ajit Solanki/AP Photo)

The Tree Projects team spent 67 days documenting one eucalyptus regnans in the Styx valley of Tasmania. Using a combination of tree-climbing and elaborate arboreal rigging techniques, they produced an intimate portrait from an impossible perspective of one of the world’s largest individual flowering trees, which goes by several common names. These photos document the process that resulted in an extraordinary ultra high-definition photograph. Here: Haley nears the top of the tree. (Photo by Steven Pearce/The Tree Projects/The Guardian)

Devotees walk through the woods of Changu Narayan as they arrive to perform rituals and prayers during the Swasthani Bratakatha festival in Bhaktapur, Nepal February 8, 2017. (Photo by Navesh Chitrakar/Reuters)

A man sits waiting for a train on the London Underground in 1890, when the platform floors were still made from wooden floorboards. (Photo by Hi-Story/Alamy Stock Photo)