About £3m has been spent making Hydebank Wood jail on the outskirts of Belfast more family friendly.
Authorities said it was not about making life cosy
The Young Offenders' Centre, which now incorporates Northern Ireland's only women's prison, deals with hundreds of visitors a month.
Many of those are children going to see a parent.
Hydebank Wood is home to more than 200 prisoners, most of them young offenders aged 16 to 21, along with 30 female inmates.
The new family visits complex is aimed at softening the regime for visits by husbands, wives, partners and children of those being held in the jail.
But the authorities said it was not about making life cosy for inmates, who receive 1,600 visitors a month, not including children.
Governor Stephen Davis said: "This is still a prison and it will always be a prison.
"What we have done is look at the needs of families and prisoners and looked at what actually works and prevents prisoners from coming back in.
"What we hope to do is maintain the family unit and maintain prisoners in a settled environment whenever they leave prison."
Olwen Lyner of the Northern Ireland Association for the Care and Resettlement of Offenders (NIACRO) said the prison environment was a strange place for everyone visiting it.
"All the research suggests that if there is a family prepared to engage with the prisoner throughout the period and there to welcome him back when he comes out of prison - that is one of the most important things in terms of having a settled lifestyle on release," she said.