A tunnel with electric switches are seen in Josip Broz Tito's underground secret bunker (ARK) in Konjic, October 16, 2014. In the early 1950s, Josip Broz Tito, the late leader of the former Yugoslavia, ordered the building of the secret bunker, located 900 feet (270 m) underground and near the Bosnian town of Konjic, to safeguard the country's ruling class in case of a nuclear attack. Construction at the complex, which had a cost equivalent price tag of $4.6 billion, continued until 1979, the year before Tito died. (Photo by Dado Ruvic/Reuters)

HIV-positive 71-year-old Sylverio Hachiploa (R) talks with caregivers Glandwel Muleya (L) and Sister Abigail Mwaka Mazuba (C) in his thatched hut during a visit by a home-based care team in the village of Nedwmba, south of the Chikuni Mission in the south of Zambia February 23, 2015. The caregivers in the Jesuit-run home-based care project at the Chikuni Mission run a capacity-building and empowerment project at the household level, offering training and assistance in crop-growing and animal rearing, as well as offering companionship, pastoral care and monitoring of the antiretroviral treatment compliance of HIV-AIDS patients. (Photo by Darrin Zammit Lupi/Reuters)

Kieron Connolly’s new book of photographs of more than 100 once-busy and often elegant buildings gives an idea of how the world might look if humankind disappeared. Here: Bodie, Mono County, California. Gold was discovered at Bodie in 1859 (just after the initial California gold rush) and it went from mining camp to boomtown. Its decline began in 1880, when word spread of new boomtowns elsewhere. The Standard Consolidated Mine closed in 1913, and four years later the Bodie Railway was abandoned. By 1940 the population was down to 40. Today, Bodie is maintained in a state of arrested decay as a visitor attraction. (Photo by Alamy Stock Photo)

Though schools around the globe have different start dates, calendars and traditions, the first day of a new term is an exciting time filled with the prospects of gaining more knowledge, making new friends and building community. Here: Schoolchildren attend their first lesson on Knowledge Day in the town of Turov, Zhytkavichy District, Gomel Region, Belarus on September 1, 2017. Knowledge Day marks the beginning of a new school year in Belarus and is celebrated on September 1. (Photo by Viktor Drachev/TASS via Getty Images)

Shot by Bert Hardy, the black and white images show prisoners carrying out remedial tasks such as untying knots in post office string and sewing mail bags. Other intriguing shots show lags doing their daily one hour outdoor exercise, being frisked for contraband items by officers during a routine “rub down” and serving evening meals. Strangeways was designed by Alfred Waterhouse and cost £170,000 ($207,910) to build. The prison, famed for its prominent ventilation tower and imposing design, has become a local landmark. Here: A prison officer frisking prisoners during the “rub-down” at Strangeways Prison in Manchester, UK on November 1948. (Photo by Bert Hardy/Picture Post/Hulton Archive/Getty Images)

The Haʻikū Stairs, also known as the Stairway to Heaven or Haʻikū Ladder, is a steep hiking trail on the island of Oʻahu. The trail began as a wooden ladder spiked to the cliff on the south side of the Haʻikū Valley. It was installed in 1942 to enable antenna cables to be strung from one side of the cliffs above Haʻikū Valley to the other. A building to provide a continuous communication link between Wahiawā and Haʻikū Valley Naval Radio Station was constructed at the peak of Puʻukeahiakahoe, elevation about 2,800 feet (850 m). The antennae transmitted very low frequency radio signals from a 200,000-watt Alexanderson alternator in the center of Haʻikū valley. The signals could reach US Navy submarines as far away as Tokyo Bay while the submarines were submerged.

“These creepy pictures of abandoned asylums, prisons and schools give a sense of what life was like in institutions of 20th century America. Photographer Daniel Barter, 30, captured on film bowling alleys, theatres and hairdressing salons all completely intact. The Londoner was on travelling through Americas north eastern states when he had the chance to explore the derelict public buildings left untouched since their last inhabitants shut the doors”. – Caters News. Photo: Salon equipment inside a sanatorium in New York. (Photo by Daniel Barter/Caters News)

Police, bystanders and soldiers aid a fallen soldier at the War Memorial as police respond to an apparent terrorist attack on October 22, 2014 in Ottawa, Canada. A gunman is believed to have shot a soldier as he was standing guard at the National War Memorial in Ottawa. It is believed police then chased the man into the main parliament building at Parliament Hill, where more shots were fired. (Photo by Wayne Cuddington/Postmedia/Barcroft Media/ABACAPress)