The Ha’iku Stairs, aptly nicknamed the Stairway to Heaven, are a steep climb on the island of O’ahu that seems to disappear into the sky itself.

The trail got its start as a simple wooden ladder attached to the cliff. It was installed during World War II to facilitate the building of a giant VLF transmitter. Unlike other VLF-transmitters, this station did not use any towers, but instead used antenna cables spun between the cliffs above Ha’iku Valley. These, along with a building at the peak, could transmit signals that could reach submarines as far away as Tokyo Bay, even when they were submerged underwater.

At the end of the 1960s the transmitter was transformed into a station for the OMEGA navigation system, which remained until the system was shutdown on September 30th, 1997.

In the 1950s, the wooden stairs were replaced by metal steps and ramps—3,922 steps in all. The trail was officially closed in 1987, and “No Trespassing” signs put up at the site.

Note: It is illegal in Hawai’i to climb these stairs. Most days a guard is posted at the foot to stop people from climbing them.