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)

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.

Grand banqueting halls, opulent lobbies and vast ballrooms; you could easily be forgiven for thinking this was a collection of photographs was documenting some of Europe’s grandest hotels. However, a closer look will reveal the majestic rooms to be engulfed in swathes of dust and moss; hotels that once hosted royals and high society abandoned to the elements. This is the latest result of urban exploration photography, going beyond “no entry” signs to capture images of dilapidated buildings across Europe. IT worker Thomas Windisch, from Graz in Austria, indulged his passion for photography by traveling across the continent, visiting over 100 abandoned hotels along the way. Here: inside a hotel in Austria. (Photo by Thomas Windisch/Caters News)

“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)

Lebanese students dance during “The Big Dance” event in downtown Beirut, near the parliament May 9, 2015. About 1000 students from all over Lebanon gather and take part in a joint dance with the aim of encouraging people to get into dance and increase fitness levels. This initiative is part of the British Council's project, Connecting Classrooms which aims at building links between schools in the UK and Lebanon. (Photo by Aziz Taher/Reuters)

Fireplace for children, Trondheim, Norway, by Haugen/Zohar. The children of Trondheim come to sit around the fire and tell stories in this whimsical cone hut, made with materials recycled from a construction site. (Photo by Jason Havneraas/The Guardian)

Participants wearing costumes and masks take part in the first day of the traditional carnival parade in Mohacs, Hungary, 23 February 2017. The carnival parade of so-called busos, dressed in costumes with frightening wooden masks and using various noisy wooden rattlers, is traditionally held on the seventh weekend before Easter to drive away winter. (Photo by Sandor Ujvari/EPA)

HRP-4C, a five-foot humanoid robot developed at Japan's National Institute of Advanced Industrial Science and Technology, sings and dances with performers at the Digital Contents Expo in Tokyo on October 17, 2010. The robot runs entertainment software called Choreonoid, a name formed from the words “choreograph” and “humanoid”. (Yoshikazu Tsuno/AFP)