[4] In 1909, plans were drawn up for a new "quiet and chronic"[This quote needs a citation] block to relieve overcrowding in the male wards at the Claremont hospital.

The block was placed in an isolated position, adjacent to the dairy farm, and approximately 800 metres (0.5 mi) to the east of the main Claremont Hospital for the Insane site.

X Block was completed by 1910–11 at a cost of £A 24,789, equivalent to A$3.8 million in 2022, and accommodated 150 patients, who worked in the adjoining farm, associated gardens and orchards located on the hospital site.

This was later renovated for use as an early treatment and admissions centre, outpatients clinic and infirmary, which became part of the original Graylands Hospital complex in 1972 and was called Victoria House.

Incoming Inspector General of the Insane Dr Digby Moynagh had Montrose House renovated and on 17 April 1959 the building was re-opened as Australia's first psychiatric day hospital.

The Graylands Day Hospital continued to operate on the site until it moved to Shenton Park in the 1960s, and the building was resumed for ward purposes and renamed Riverton House in 1967.

Swanbourne Hospital was created consisting of the original 1904 buildings and was established to primarily treat psycho-geriatric patients and adults with developmental disabilities.

The earliest buildings being the former X block, the former kitchen (becoming the patient library and Pastoral Centre) and former dining room (becoming Anderson Hall) as well as Gascoyne House.

In the mid-1980s, the old Claremont Hospital sports ground (including the old tuberculosis block) was sold, and John XXIII College was constructed on the site.

In 1993, the Frankland Centre was opened at the Graylands campus to house the WA State Forensic Mental Health Service.