In this photo taken Tuesday, October 14, 2014, skulls and bones are stacked at the Catacombs in Paris, France. The subterranean tunnels, stretching 2 kilometers (1.24 miles), cradle the bones of some 6 million Parisians from centuries past and once gave refuge to smugglers. The site used to close at 5 p.m., but is now staying open until 8 p.m. The change is mainly aimed at allowing more people to visit and reducing long lines, since it can only hold a limited number of people at a time and visits can't be reserved in advance. (Photo by Francois Mori/AP Photo)

A tourist reacts as an elephant sprays her with water in celebration of the Songkran water festival in Thailand's Ayutthaya province, April 9, 2014. Songkran, the most celebrated festival of the year, marks the start of Thailand's traditional New Year. (Photo by Chaiwat Subprasom/Reuters)

These photographs are the work of urban explorer Dr Bradley Garrett who made headlines back in 2012 when he posted a series of snaps from the top of The Shard skyscraper while it was still under construction. Garrett, now a researcher at the University of Oxford, took these shots during his time with the London Consolidation Crew (LCC), a loose collection of urban explorers based in the English capital. Photo: Bradley Garrett stands on the edge of the Ritz-Carlton Chicago as lightning strikes in the distance in Chicago, US. (Photo by Bradley L. Garrett/Barcroft Media)

A man reacts while having a nasal swab sample taken at a testing and screening facility for the coronavirus, in a hospital in Karachi, Pakistan, Friday, August 21, 2020. (Photo by Fareed Khan/AP Photo)

Men dressed in protective suits stand around the coffin of Kenyan doctor Daniel Alushula who died of coronavirus disease (COVID-19), during his funeral in the village of Khumusalaba, in Kakamega county, Kenya on November 13, 2020. (Photo by Baz Ratner/Reuters)

Ellen MacRae a student from Edinburgh University take a lateral flow antigen test at a test centre which is also open to students in Edinburgh Napier University, Queen Margaret University and SRUC on December 1, 2020 in Edinburgh, Scotland. The programme is running in partnership between the University of Edinburgh and other Scottish universities, the Scottish Government and NHS Test and Protect, supporting students leaving their term-time accommodation to travel home at the end of term for the winter break. (Photo by Jeff J. Mitchell/Getty Images)

A seagull files over a man sitting at a coffee shop backdropped by the Bosporus Strait in Istanbul, Tuesday, November 17, 2020. (Photo by Emrah Gurel/AP Photo)

An injured person reacts during a protest against the new government of President Manuel Merino, in San Martin de Lima square, in Lima, Peru, 14 November 2020. Merino took office on 10 November amid a controversial constitutional process after the dismissal of former President Martin Vizcarra for “moral incapacity” by Peruvian Congress. (Photo by Aldair Mejia/EPA/EFE)