With dozens of spiritual counselling rooms, a gym, cafe, sauna, and even recording studios, sprawling over 13,500 square metres, it sounds like a spa resort.

Key points: A 24-year-old man died after being stabbed in the neck at the Scientology headquarters yesterday

A 24-year-old man died after being stabbed in the neck at the Scientology headquarters yesterday A 16-year-old boy was arrested over the alleged attack and is yet to be charged

A 16-year-old boy was arrested over the alleged attack and is yet to be charged The building opened in 2016 and was expected to herald a "golden age" for Scientology

But this "architectural masterpiece" on Sydney's north shore is actually the Church of Scientology's largest centre outside the United States.

It also became the site of an alleged stabbing which claimed the life of a 24-year-old on Thursday.

Known as the Advanced Organization and Saint Hill ANZO by the church, the building was opened in Chatswood in 2016 as a spiritual centre for the entire Asia-Pacific region.

According to the Church, the opening of the centre, attended by more than 2,500 Scientologists, was expected to herald a "golden age" for Scientology.

The centre houses 60 auditing rooms, where church members receive spiritual guidance, as well as training sites for new auditors.

According to the organisation, an auditing procedure rids people of "spiritual disabilities" and increases "spiritual abilities".

Spokeswoman Sei Kato shows off the Church of Scientology's Chatswood headquarters in 2016. ( Supplied: Fairfax Media )

The centre also has "advanced" Scientology materials that have been translated into 17 languages including Chinese and Japanese.

It was designed as a modern structure with "multi-story glass blending into a striking concrete landscape".

Situated right next to the Lane Cove National Park and Blue Gum Creek, the Church says the site is a "virtual Garden of Eden".

Promotional material of the building's 2016 opening (L) and the building pictured on Thursday. ( Supplied/ABC News )

A 16-year-old boy was arrested over the alleged stabbing but is yet to be charged.

He was seen being led out of the complex in handcuffs yesterday.

Police swarmed the complex after the alleged attack and the two victims were taken to Royal North Shore Hospital, where the 24-year-old died from a wound to his neck.

Police said the accused boy produced a knife that was about 25cm long as he was being escorted off the property by two Scientology employees.

The boy had a "lawful reason" for being at the centre, according to Detective Chief Inspector Simon Jones.

In a statement yesterday the Church said the victim was a "beloved member".