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.

Tourists enjoy the rare opportunity to walk in water as they visit Badwater Basin, the normally driest place in the US, in Death Valley National Park, Inyo County, California on February 18, 2024. Badwater Basin, an endorheic basin in Death Valley National Park, was flooded by Hurricane Hilary in August 2023 and recent rains in California. It is the lowest point in North America, at 282 feet (86 meters) below sea level. (Photo by David Swanson/AFP Photo)

A visitor jumps for a photograph on the world's highest and longest glass-bottomed bridge above a valley in Zhangjiajie in China's Hunan Province on August 21, 2016. The bridge, which opened to the public on a trial basis on Saturday, spans 430 meters (1,410 feet) and rises about 300 meters (984 feet) above a valley in a scenic zone, making it the world's highest and longest glass-bottomed bridge according to Chinese state media. (Photo by Fred Dufour/AFP Photo)

A man stands on a mountain summit as he looks over the Inntal valley in the western Austrian village of Gnadenwald, Austria on July 18, 2017. (Photo by Dominic Ebenbichler/Reuters)

California “weed nun” Christine Meeusen, 57, (R), and India Delgado, who goes by the name Sister Eevee, smoke a joint at Sisters of the Valley near Merced, California, April 18, 2017. (Photo by Lucy Nicholson/Reuters)

Yogis, Israeli and foreigners, participate in the Arava Yoga Annual festival at the ancient copper mines area of the Timna Valley, in the southern Arava region of Israel, north of Eilat on November 2, 2018. (Photo by Menahem Kahana/AFP Photo)

Festivalgoers are seen during the 2019 Coachella Valley Music And Arts Festival on April 20, 2019 in Indio, California. (Photo by Emma McIntyre/Getty Images for Coachella)

Run by the Society of German Nature Photographers (Gesellschaft Deutscher Tierfotografen), the prestigious annual contest celebrates the best wildlife photography from members in Germany. Here: Landscapes, second place: Florian Smit, “Rainforest” (Danum valley, Borneo). (Photo by Florian Smit/2019 GDT Nature Photographer of the Year)