Mystery of man who vanished after taking eerie final photo while hiking ‘Stairway to Heaven’

A man vanished while hiking the 'Stairway to Heaven' and one of the final photographs he sent to his grandma is particularly hair-raising.

Teenager Daylenn Pua went on a hiking trip during his visit to Hawaii to see his grandmother and decided to tackle the Haiku Stairs - also known as the 'Stairway to Heaven' - on February 27, 2015.

However, after sending photographs of his hike to his grandma, the 17-year-old would never be heard from again.

Daylenn Pua went missing in 2015 (Family handout)

Daylenn's grandmother had warned him about the Haiku Stairs - the pathway having been closed to the public and it considered trespassing to attempt the climb.

The steps were built in World War Two to provide access to a top-secret US Navy radio station hidden in Haiku Valley - the US able to use the base to transmit signals to its ships in the Pacific, even as far as Tokyo Bay.

The path consists of '3,922 steps across the Ko'olau range' However, the stairs are 'weathered and sometimes not trustworthy' the hike up a 'continuous and steep path' considered extremely dangerous to try and navigate, Oahu Hike states.

However, the teen went anyway - the stairway leading to 'easily the best views across Oahu' - a post to social media the day before the hike showing Daylenn asking followers to wish him 'luck'.

Alas, Daylenn has never been seen again, his grandmother left only with several photographs he sent her from during his hike.

One of the photos Daylenn sent to his grandmother (Daylenn Pusa)

US navy drones were sent to try and find any sign of Daylenn and search parties were conducted, however, neither the teen nor his phone or backpack were located.

There are subsequently only two main theories as to what happened - one a result of a photograph the teen sent to his grandmother.

If you zoom in on the image, you can spot a figure of someone - or something - seemingly crouching in the undergrowth.

It's not been ascertained whether this is actually a person or animal, what they were doing at the location and whether or not they're related to Daylenn's disappearance, however, Honolulu Police Department determined if it was a man in the image, they would be considered a person of interest in the investigation.

Another possible explanation is Daylenn slip and fell - rescue teams searching for the teen reporting slipping and falling themselves despite being experienced hikers.

Ultimately, it remains unknown what happened to Daylenn even nearly 10 years on since he vanished.

UNILAD has contacted Honolulu Police Department for comment.