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.

Undated BBC handout photo of a female two-coloured Mason Bee carrying a dried grass stalk back to her snail-shell nest on the British Isles in the latest episode of Sir David Attenborough's Wild Isles series. Issue date: Sunday March 26, 2023. (Photo by John Walters/Silverback Films/BBC/PA Wire)

These photographs of hundreds of ducks following their leader down a river are truly mesmerizing. Rafeur Rahman of Bangladesh climbed a high bridge and saw hundreds of ducks apparently playing a game of follow the leader. More than 500 ducks live on the river, where the mosses and snails provide the perfect habitat. Here: Ducks in the river Baral in Bangladesh. (Photo by Rafeur Rahman/Caters News Agency)

A long exposure image shows star trails from the abandoned submerged orthodox church of St. Nicholas without roof, submerged in the Mavrovo Lake, near Mavrovi Anovi, North Macedonia, 17 March 2019. Constructed in 1850 and submerged in 1952 due to the construction of the hydro system Mavrovo, the church St. Nicholas continues to attract the attention of almost every visitor as it peaks from the water. (Photo by Georgi Licovski/EPA/EFE)

Standalone picture dated June 7th, 2022 shows Flt Lt Adam O’Hare rehearsing in the iconic Typhoon plane over Lincolnshire yesterday (Tues) as he trains for this summers airshows with vapour trails over the wing. The phenomenon is caused by low pressure areas created on the aircraft's skin and wings as it moves through moist air. As the pressure drops so does the temperature, and if the temperature reaches the saturation point, water vapor is created. (Photo by Claire Hartley/Bav Media)

A gannet grabs a fish by its beak, 2014, in Shetland, Scotland. Hundreds of gannets crash into the sea in search of food – leaving a trail of air bubbles in their wake. Richard Shucksmith, 41, on the Shetland Isles, Scotland captured the remarkable scene as he took a boat to feed the large colony of seabirds that nested on the cliffs. The photographer has taken images of the gannets every summer for the last three years as the birds gather on the cliffs to breed. (Photo by Richard Shucksmith/Barcroft media)

Schoolchildren look at a lifelike animatronics display of a dinosaur at the dinosaur-themed Zoo-rassic Park in Singapore on November 16, 2016. To raise awareness on the sixth mass extinction, the Singapore Zoo and River Safari displayed lifelike dinosaur animatronics where visitors can trail along the Dinosaur Valley which does not involve living animals. (Photo by Roslan Rahman/AFP Photo)

An army cadet contestant with his kart trailing smoke hits the ramp hard and crashes during the 70 year anniversary soap box derby on April 02, 2023 in Hunstanton, England. Over 40 home built karts raced through the streets of the Norfolk town, around bends and over jumps. The race was first held in1953. (Photo by Martin Pope/Getty Images)