Meet the star students of orangutan school – the unique rehab centre where orphaned apes are taught how to climb trees and survive in the wild without their mum and dad. (Photo by Caters News)

In this Tuesday, August 27, 2019, file photo, a climber stops to take pictures of clouds while climbing towards the summit of Mount Fuji to watch the sunrise, in Japan. (Photo by Jae C. Hong/AP Photo/File)

Natalia Grossman of the USA competes during the women's finals of the IFSC Climbing World Cup Meiringen on April 09, 2022 in Meiringen, Switzerland. (Photo by Marco Kost/Getty Images)

“La Diablada” dancers take part in a celebration in honor of the Virgin del Carmen, patron saint of Chile, in Santiago, Chile, Saturday, July 16, 2022. Hundreds of cowboys in woolen ponchos and families on wooden horse carts lined up to receive a priest's blessing in the huge esplanade in front of the National Sanctuary of Maipu on Saturday afternoon. (Photo by Esteban Felix/AP Photo)

Monkeys climb onto tourists during the annual Monkey Festival, after officials start capturing monkeys, in Lopburi province, Thailand, on November 24, 2024. (Photo by Patipat Janthong/Reuters)

Palestinians fleeing Khan Yunis on the coastal road leading to Rafah further south ride on a donkey-cart with their belongings on January 25, 2024, amid continuing battles between Israel and the Palestinian militant group Hamas. Israel pressed its blistering assault on the Gazan city of Khan Yunis on January 25, with the Palestinian Islamist movement Hamas saying dozens were killed in heavy bombardment and urban combat. (Photo by 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.