A daredevil has climbed to one of the highest points in Sydney, scaling a crane on top of a city skyscraper without any safety equipment in an act police have described as “absolutely stupid.”

The young climber was filmed almost 300 metres in the air atop one of Sydney’s tallest cranes, with footage posted to social media showing the terrifying ascent.

WATCH THE VIDEO ABOVE: Daredevil scales Sydney crane in ‘stupid’ stunt

Know the news with the 7NEWS app: Download today

The man snuck into the construction site at 55 Pitt Street, making it past security before scaling scaffolding and climbing 40 flights of stairs.

He then hung out over the edge to climb even higher, going step by step until he reached the top of the crane.

“Absolutely stupid,” NSW Police Commissioner Mal Lanyon said of the dangerous stunt.

“There is no activity to go onto social media that’s putting yourself at this type of risk.”

He scaled the 300 metre tall crane in Sydney. Credit: 7NEWS

The climber agreed to speak anonymously with 7NEWS about his motivations.

“I like to think of it as more of a challenge. And just knowing that I can do that makes me want to,” he said.

It’s not the first time the daredevil has attempted such a dangerous feat. Last year, he posted video of himself climbing a crane in Parramatta.

The view from the ground is dizzying, let alone from 250 metres in the air where one slip could prove fatal.

Security has now been tightened at the 55 Pitt Street site, which is set to become one of Sydney’s biggest office skyscrapers.

When asked if he would stop, the climber said: “I don’t think so.”