High on a hill at Mount Claremont, the boarded-up former Claremont Hospital for the Insane is a grim reminder of the brutal way people with mental illness were once treated.

Now surrounded by suburbia and adjoining the current Graylands mental health hospital, the imposing red brick building of the former insane asylum has stood vacant and boarded up since 1986.

There are now plans to redevelop the site into an aged care facility, with its grand former dining room, Montgomery Hall, to be available for weddings and theatre productions when the work is complete.

Mental health care in a less enlightened era

Nurses and staff at the Claremont Hospital for the Insane in 1917. ( Supplied: State Library of WA )

Heritage Perth chief executive Richard Offen told 720 ABC Perth that Western Australia's mental health facilities went back more than 150 years.

"The care of the mentally ill in WA began with the creation of the Fremantle Lunatic Asylum, which opened in July 1865," he said.

"There were more patients than could be accommodated, so in 1897 the Whitby Falls mental hospital was added to the mental health scheme.

"In 1900 a parliamentary committee was formed to enquire into the mental hospitals and found that Fremantle Asylum was totally unfit for purpose."

In 1901, an article in the Sunday Times described the conditions in Fremantle Asylum as "worse than an open cesspit in a citizen's back yard, for the inmates are immured from escape from it and are obliged to endure its sickening stench from weary day to day".

"How can a lunatic be cured of his filthy habits when the grounds on which he is literally imprisoned present such filth to his eyes and his nostrils every hour of the day?" the article went on to ask.

In 1901 the State Government appointed Dr Sydney Montgomery as superintendent for the Fremantle Asylum.

"Dr Montgomery and John Grainger, who was the principal architect at the Public Works Department, went to the eastern states to see how they were catering for the mentally ill and the sort of institutions they had built," Mr Offen said.

The entry to the Claremont Hospital for the Insane in 1928. ( Supplied: State Library of WA )

The result was that land at Claremont, then mostly untouched bushland, was set aside to build a new hospital.

"There was a new Lunacy Act passed in 1903 and they set up temporary buildings here for the patients they classed as 'quiet and chronic'," he said.

Those early patients were put to work clearing the scrub, and by 1904 the male wards were under construction.

"The wards that were built had several categories — recent and acute, the sick and infirm, the epileptic, and the violent and noisy.

"In 1920 a film projection box was added to the building so that the entertainment could include the movies."

Woman spent 40 years in an institution

Despite the improved buildings, treatment for many of the patients at the hospital offered little in the early 20th century.

Jess Barratt has researched her great-grandmother Matilda Maria Hurst's history as a patient at the hospital.

Ms Hurst died at the hospital in 1934, having spent 40 years institutionalised in Fremantle and after 1908, at Claremont.

"A new home didn't seem to change Matilda and in the early years it appeared to make her worse," Ms Barratt wrote of her research.

"The case book for the Claremont Hospital for Insane starts in 1908 and ends in 1918.

"It was noted throughout 1908, 1909, 1910 and 1911 that she was very destructive at times, untidy, violent, troublesome, dirty in habits and often tore at her clothing."

The old Montgomery Hall at Claremont Hospital in 2012. ( Supplied: Jess Barratt )

Mr Offen said "treatment was gradually moving forward" during this era and Claremont continued as the main hospital for the mentally in Perth up until 1975.

The site was then divided into Graylands Hospital, which still operates today as WA's largest mental health facility, and the older buildings became Swanbourne Hospital.

The boarded up buildings on the old Claremont hospital site in 2012. ( Supplied: Jess Barratt )

In 1986 Swanbourne Hospital closed, and the old red brick buildings, including the administration block and Montgomery Hall, were boarded up.

"The whole complex is on the state heritage register and it is a very fine building, and significant not only for its architecture but also its social history," Mr Offen said.

"The site was pretty much vacant from 1986 and various proposal for re-use were put forward, but fell through."

The site became popular with vandals, ghost hunters and photographers as various developments were rejected by the local community.

In 2012 an aged care company bought the remaining buildings and is in the process of restoring the heritage buildings to create an 80-bed aged care home.