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.

Japan's electronics equipment maker MuRata Manufacturing Co., Ltd's showcased their bicycle-riding robot “MuRata Boy” during the CEATEC Japan 2006 exhibition on October 3, 2006 in Chiba, Japan. The “MuRata Boy” robot can ride up a 25-degree slope, stop without losing its balance and make an S-curve without falling. (Photo by Koichi Kamoshida/Getty Images)

Japan's ON-ART Corp's staff repaints the company's eight metre tall man-operated walking dinosaur robot “TRX03” at the company's studio in Tokorozawa, Japan, December 6, 2016. (Photo by Toru Hanai/Reuters)

A woman looks at head of bluefin tuna on display in front of a store at Tsukiji fish market in Tokyo, Monday, February 19, 2018. The large bluefin are particularly valuable in Japan, where they are considered a premium sushi and sashimi fish. A single fish sold for more than $1.75 million at an auction in Japan in 2013. (Photo by Koji Sasahara/AP Photo)

A fan of Japan reacts after Crotia winning the penalty shoot out during the FIFA World Cup Qatar 2022 Round of 16 match between Japan and Croatia at Al Janoub Stadium on December 5, 2022 in Al Wakrah, Qatar. (Photo by John Sibley/Reuters)

Members of Team Japan compete in the Artistic Swimming Team Acrobatic Final on day four of the Fukuoka 2023 World Aquatics Championships at Marine Messe Fukuoka Hall A on July 17, 2023 in Fukuoka, Japan. (Photo by Quinn Rooney/Getty Images)

Newly hired employees for Japan Airlines (JAL) attend an entrance ceremony in a hangar at Haneda Airport on April 03, 2023 in Tokyo, Japan. 2,000 new employees from 37 JAL group companies were welcomed at the event held for the first time in four years following a hiatus due to the coronavirus pandemic. (Photo by Tomohiro Ohsumi/Getty Images)

MotoGP Ducati Lenovo Team rider Marc Marquez (R) of Spain and his girlfriend Gemma Pinto (L) celebrate his World Champion 2025 title after the race at the Motorcycling Grand Prix of Japan in Motegi, Tochigi Prefecture, northeastern Japan, 28 September 2025. (Photo by Franck Robichon/EPA)