This image obtained January 31, 2017 from the US Geological Survey's Hawaiian Volcano Observatory showing a lava stream, pouring out of the lava tube on the sea cliff at the Kamokuna ocean entry from the Kilauea Volcano on January 29. (Photo by AFP Photo/USGS)

A classic American car is wrapped in plastic to prevent sea salt from corroding it in Havana, Cuba, Tuesday, March 2, 2021. Vintage cars in Cuba are part of daily life with most classic cars being used as taxis and to transport tourists. (Photo by Ramon Espinosa/AP Photo)

High waves batter a breakwater at a port at Kihou town in Mie prefecture, central Japan on October 6, 2014. Strong typhoon Phanfone slammed into Japan, packing gusts and huge waves that have already swept three US military officials out to sea, as it made a beeline for Tokyo. (Photo by AFP Photo/Jiji Press)

Workers adjust rails at the bed of a drained area of a lake used for the production of salt at the Sasyk-Sivash lake near the city of Yevpatoria, Crimea, September 25, 2015. The area has a long tradition of salt production, prepared from salt flats flooded with water from the Black Sea. (Photo by Pavel Rebrov/Reuters)

Volunteers use flour to clean birds following an oil spill caused by an incident involving two tankers damaged in a storm in the Kerch Strait, in the village of Vityazevo near the Black Sea resort of Anapa, Russia on December 20, 2024. (Photo by Sergey Pivovarov/Reuters)

Kevin Jay and Nigel Cox perform some light painting on the beach at Frinton-on-Sea in Essex, UK using colour changing LED light wands during a 25-second exposure on March 4, 2024. (Photo by Kevin Jay/Picture Exclusive)

An armed demonstrator lifting a Palestinian and Yemeni flags gestures during an anti-Israel and anti-US rally in the Huthi-controlled capital Sanaa on January 19, 2024, protesting the US designation of Yemen's Huthi rebels as “terrorists”, after a series of attacks on Red Sea shipping amid ongoing battles between Israel and the militant Hamas group in Gaza. (Photo by Mohammed Huwais/AFP Photo)

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.