Machu Picchu, Peru. A llama’s-eye view of the legendary Inca settlement at Machu Picchu, isolated high in the Peruvian Andes. (Photo by Jim Turner/National Geographic)

People pose for photos among a field of cosmos flowers in a car park before high-rise apartment buildings in Goyang, west of Seoul on September 22, 2020. (Photo by Ed Jones/AFP Photo)

Dinosaur costumed actors representing Thailand's establishment at a high school student led protest in Bangkok, Thailand on November 21, 2020. (Photo by Matthew Tostevin/Reuters)

A 16-meter-high snowman is nearly completed by the Songhua River in Harbin City, northeast China's Heilongjiang Province on December 7, 2022. (Photo by Rex Features/Shutterstock)

Urte Baikstyte, of Lithuania, fails an attempt in the Women High Jump qualification at the European Athletics Indoor Championships at Atakoy Arena in Istanbul, Turkey, Thursday, March 2, 2023. (Photo by Khalil Hamra/AP Photo)

This aerial photograph shows a stork with two chicks on a nest installed on a high voltage line mast in Bouee, western France, on June 3, 2025. (Photo by Loïc Venance/AFP Photo)

Yaroslava Mahuchikh of Ukraine in action during the High Jump in the Meeting de Paris, part of the 2025 Diamond League at Stade Charlety on June 20, 2025 in Paris, France. (Photo by Gonzalo Fuentes/Reuters)

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.