Online sleuths have scrambled to uncover what’s at the end Sydney’s most mysterious staircase – and what they found is simply stunning.

Sydney’s iconic Queen Victoria Building keeps many secrets, with one, in particular, capturing the imagination of curious souls online in recent days.

A narrow, winding staircase leading to a mysterious door smack-bang in the middle of the 124-year-old shopping mall is the building’s latest feature to spark online discussion.

News.com.au in 2020 revealed exactly what was on the other side of the door.

It leads to the 60-metre-high stained glass dome – an iconic feature in the centre of the building that glistens in the sunlight during the day.

“I really need to know what’s behind this little door in the QVB,” a Reddit user asked the online forum on Friday.

Reddit users were again intrigued by the news, with many impressed when one user revealed its destination.

“I thought that if I knew what was at the top of the stairs, I wouldn’t want to go up them so badly. But now I just want to go up them even more,” on person wrote.

“Wowee, that is huge and awesome. I always assumed it just went out onto the roof,” another wrote.

The grand dome was also one of Sydney’s highest points during World War II, before the QBV was surrounded by skyscrapers, and was used by soldiers to watch the harbour for approaching enemy.

And it’s not just the staircase that baffles QVB visitors.

The building hosts an array of strange doors and rooms.

One is a door to room 417, which hovers almost a metre from the ground, behind a handrail in the middle of a staircase.

Guest experience manager and tour guide John Burdon told news.com.au in 2020 that there were “hidden spaces everywhere around this building”.

“It would be great if they were all secret passageways, but we’re not 100 per cent sure what they were all for. Some may have been serving areas for the dining rooms,” he said.

But room 417 was a part of the horse and carriage lifts used in the building.

The horse would step onto a flat platform, and a lever could be pulled to lower the hydraulic lift down to the basement markets,” Mr Burdon said.

They were close to the passenger lifts but were hidden behind a wall so shoppers couldn’t see the horses descending, and some doors were access points in case the lift broke down.

Reddit users shared their appreciation of the building’s beauty while discussing the staircase.

“This is so beautiful. Like the setting of a period piece film,” one said.

“I love QVB. It’s always magical in there, another said.

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