Driven by the discovery of gold in Victoria, the local population surges to over 600,000 due to immigrants arriving. The increase in population leads to a rise in crime and the need for more established prison facilities.

Between 1857 and 1864, the second phase of Pentridge Prison construction is undertaken. The perimeter walls, the administration building, A, B and the later named C and F Divisions and the Warders’ Residence are built during this period.

Within Pentridge, prison philosophy revolves around the idea that silence and solitude are the best methods of reforming prisoners. The 'separate and silent' system was continued for almost 50 years at Pentridge. Under this system, prisoners are housed in cells for 23 hours a day. One hour a day is set aside for inmates to be ‘aired’. This is carried out in wedge-shaped exercise yards called ‘airing yards’. The circular-shaped yard features a central observation tower from which the gaoler can observe the prisoners.

Also known as Panopticons, there are only eight known airing yards of this style in the world. Three of these were found at Pentridge.

The construction of a new cell block building is completed in the northern part of the prison grounds, and used as a female prison. Later known as A Division, the cell block was then used as a male prison.

Charles O’Hea, an Irish-Australian local priest, calls a public meeting to change the name of Pentridge village as residents are tired of the embarrassment of being associated with Pentridge Stockade and the prison (locally known as Pentridge also). The prison depreciated property values in the area.

A petition is signed by 191 residents and landowners and submitted to the Board of Land and Works. The government consents to the change and in March 1870, Pentridge (the district) is officially renamed Coburg. Coburg has royalist associations and proved a popular choice. Other names included Merrivale (due to Merri Creek), Tipperary, Donegal and Limerick which were suggested by Irish-born residents at the behest of local Protestants.

Within the walls of Pentridge, prisoners continue to live a life of silence and solitude. Talking is forbidden and the prisoners are addressed only by their cell numbers. Even at dinner, silence is observed, post which they are immediately sent back to their cells.

As a result of the Stawell Royal Commission, an extensive work program is implemented with a number of industries established at Pentridge including a woollen mill, tailors shop, blacksmith, carpenters workshop and timber yard.

A newly constructed cell block division at the southern end of the prison is opened as the main Female Prison at Pentridge.

Completely segregated from the male prison, the division has a female Governor and female prison guards.

The Melbourne Gaol closes and Pentridge supersedes it as the main remand and reception prison for the metropolitan area.

The purpose-built women’s prison, H.M. Prison Fairlea is constructed. The opening of Fairlea brings to an end, the use of Pentridge as a permanent women’s prison.

The cell block building previously used to hold female prisoners becomes the Metropolitan Gaol for prisoners on remand, and now known as D Division.

Following a series of escapes which placed the spotlight on a lack of security at Pentridge, the eastern section of A Division and the labour yards were sealed off to create a new, maximum security section known as H Division. This division then held Victoria’s most troublesome, violent and dangerous prisoners.

Ronald Ryan is hanged at D Division Pentridge and becomes the last person to be legally hanged in Australia. Sentenced to death, Ryan was found guilty of shooting and killing prison warder George Hodson during an escape from Pentridge.

In 1985, the death penalty is abolished in all states of Australia.

Conditions in the C Division prison cells are grossly outdated — harsh and inhumane with prisoners provided only a blanket, horsehair sleeping mat and bucket. There are no lavatories.

A time of unrest, the year witnessed much political and social radicalism. Scrutiny on the treatment of criminals highlighted their rights, bringing the concept of prison reform to the fore.

C Division (prison cell block) is demolished. The structure was deemed inhumane long before; prisoners used buckets as toilets, and for years there was no electricity.

Jika Jika, later to be known as K Division, opens as a new maximum-security division, designed to house the more troublesome prisoners formerly held in H Division.

A fire in K Division is started by inmates and results in the death of five prisoners. The maximum-security division is closed immediately, a mere eight years after opening.

Pentridge officially closed on 1 May 1997, ceasing all operations as a prison. Most prisoners are relocated to H.M. Prison Barwon.

In 1999, the State Government of Victoria sells Pentridge to developers Crema and Barbon in partnership with the Chiavaroli’s.