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.

A dog walks past a handmade replica of Lamborghini Diablo outside a garage rented by Wang Yu and Li Lintao on the outskirts of Beijing, August 21, 2014. Chinese race car enthusiasts Wang Yu and Li Lintao, both in their 30s, have finished designing and making two replicas of the Lamborghini Diablo, which can reach the top speed of 310km/h, and are currently working on a replica of the T-Rex motorcycle. They spent approximately 5 million yuan (around USD 811,899) to buy parts and hire workers, and about 6 years to assemble them with the knowledge they gained from studying mechanology for nearly a decade abroad. Wang and Li went popular after showing their first handmade replica of Lamborghini Diablo at the Beijing International Automobile Exhibition in 2012, and sold their second Lamborghini replica to Alibaba as a collection. (Photo by Petar Kujundzic/Reuters)

In this photograph taken on February 15, 2021, doctor Sergen Saracoglu (L) and nurse Yilzdiz Ayten (C) from the Bahcesaray public hospital vaccination team, arrive at the village of Guneyyamac in eastern Turkey, as part of an expedition to vaccinate residents of 65 years old or above with Sinovac's CoronaVac Covid-19 vaccine. (Photo by Bulent Kilic/AFP Photo)

Rows of workers shelter under umbrellas from the scorching heat as they painstakingly sort through a red carpet of millions of chilli peppers in Bogra, Bangladesh on October 3, 2023. They sort the rotten and broken chilli peppers out to separate the poor quality ones which won't sell. In a line, the pickers who are paid less than £3 for a 10-hour shift slowly move forward with their baskets to separate the bad from the good after the chilies have been dried in the sun for a week. (Photo by Joy Saha/Rex Features/Shutterstock)

In this September 1, 2014 photo released by the U.S. Geological Survey, fluid lava streams from the June 27 lava flow from the Kilauea volcano in Pahoa, Hawaii. The June 27 lava flow is named for the date it began erupting from a new vent. The Hawaiian Volcano Observatory issued a warning Thursday, September 4, 2014 to a rural community in the path of a lava flow on Hawaii's Big Island, as the molten rock moved to within a mile of homes. Observatory scientists said lava from the Kilauea volcano could reach the Kaohe Homesteads in five to seven days if it continues advancing through cracks in the earth. (Photo by AP Photo/U.S. Geological Survey)

People sit near a fully loaded in Madama near the border with Lybia on January 1, 2015. French Defence Minister Jean-Yves Le Drian paid a surprise visit to northern Niger on January 1, to visit a base being built to combat the growing flow of weapons and jihadists from neighbouring Libya. Le Drian travelled from Chad to Madama, a desert outpost about 100 kilometres from Libya, where he saw in the New Year with troops at a French base. Madama is situated on the route used by jihadists and arms smugglers in southern Libya to reach northern Mali and Niger. (Photo by Dominique Faget/AFP Photo)

The worst drought in 40 years has a cruel grip on Somalia. A struggling young government and militant violence have compounded to bring crisis to 6.7 million lives. The town of Baidoa is facing some of the harshest conditions. Surrounded by territory controlled by al-Shabaab militants and amid ongoing attacks, 160,000 people have had to leave their farms and are surviving in camps where hunger, thirst and cholera await them. (Photo by Peter Caton/Mercy Corps)

A person practices ski-joering at the Avoriaz resort in the French Alps on February 11, 2021. (Photo by Jeff Pachoud/AFP Photo)