Back in 1942, the U.S. Navy began construction of the Haʻikū Radio Station: a top secret facility that was to be used to transmit radio signals to the Navy ships that were then operating throughout the Pacific. They needed a radio transceiver and they needed it to be really high, so the peak of Puʻukeahiakahoe mountain in Hawaii was chosen. 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).
To accomplish construction, they needed “easy” access to the top of the ridges, so they installed a wooden ladder up the mountain. The pathway is still there today.
Most people refer to it as “Stairway to Heaven” but the official name, the one you’ll find on the trail head sign, is Haiku Stairs (or Haʻikū Stairs).
There’s a lot of hype around this hike because one: well, it’s amazing and two: it’s illegal to hike it due to the safety concerns. The station and trail were closed to the public in 1987. However, some hikers ignore the No Trespassing signs and continue to climb 3,922 steps.
Yet, there is a legal way of climbing this stairway to heaven. The Friends of Haiku Stairs, a volunteer group, offers legal “tours”, as long as you can contribute your time while climbing to clean up trash and help to eradicate invasive species.