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.

Storm clouds gather over the scene outside the Jewish Community Center in Leawood, Kansas following a shooting, on April 13, 2014. (Photo by John Sleezer/Kansas City Star/MCT)

Storm clouds build over a canola field near Cremona, Alberta, Friday, July 29, 2022. (Photo by Jeff McIntosh/The Canadian Press via AP Photo)

A man sledges on Primrose Hill with his daughter and their dog on February 5, 2012 in London, England. The United Kingdom is experiencing heavy snowfall with many areas affected. (Photo by Peter Macdiarmid/Getty Images)

A Southwest Airlines jet takes off from Reagan National Airport with a thunderhead to the east on June 20, 2017 in Alexandria, VA. (Photo by Jonathan Newton/The Washington Post)

The rising sun illuminates the sky above the spires of a church in Vienna, Austria, November 17, 2015. (Photo by Heinz-Peter Bader/Reuters)

A hot air balloon floats over farm fields south of Washington, Ill., as the sun slips behind clouds on the autumn afternoon of Wednesday, September 24, 2014. (Photo by Ron Johnson/AP Photo/Peoria Journal Star)

A Brussels Airlines aircraft prepares for landing in Cointrin airport during sunrise over the Mont Blanc in Geneva December 1, 2011. (Photo by Denis Balibouse/Reuters)