From today young offenders will no longer be sent to adult prisons.
Up until now, all 17-year-old boys sentenced by the courts have been detained at Wheatfield, an adult prison in Dublin.
But Children's Minister Katherine Zappone says they will now be held instead at the Oberstown Children Detention Campus in Lusk, County Dublin.
The Minister also announced that St Patrick's Institution, a penal facility for 17 to 21 year olds, is to close fully in a week's time, the 7th of April.
Fíona Ní Chinnéide of the Irish Penal Reform Trust has welcomed both developments as the closing of a "dark chapter" in Ireland's treatment of children: