A state inquiry into historical institutional child abuse in Northern Ireland will initially investigate 35 residential facilities.
The locations comprise 15 state-run children's homes, 13 institutions run by Catholic Church orders, four borstals or training schools, and three institutions run by Protestant denominations or voluntary sector organisations.
Inquiry chairman Sir Anthony Hart revealed the number as he appealed for more abuse victims to come forward to tell their stories.
The statutory probe was set up by the Northern Ireland Executive to investigate institutions run by the state and church and also those owned by the private sector or voluntary bodies from 1922 to 1995.
More than 175 people have so far contacted the inquiry to outline their experiences in care, with around 90 interviewed to date. Allegations made so far have led to the light being shone on the 35 facilities. But if more victims come forward and make further claims, more institutions could be examined.
To date the inquiry has identified more than 170 facilities which operated during the time-period, including children's homes, orphanages, industrial schools, workhouses, borstals, hospital units and schools for children with disabilities.
The majority of the 15 state-owned residential homes were run by local authorities. One was a workhouse which went out of existence just after the Second World War. Of the three non-Catholic voluntary institutions under investigation, Sir Anthony said they were either associated with a Protestant denomination or were run by a secular organisation.
On Thursday Sir Anthony launched a publicity campaign to encourage more victims to come forward. As well as promotional activity throughout the UK and the Republic of Ireland, advertising will stretch to the other side of the world.
He said: "We know that children from institutions in Northern Ireland were sent to Australia in the years after the Second World War, and there may well be people in Australia, and in other countries such as Canada and the United States, who should know that this inquiry is investigating abuse in residential institutions in Northern Ireland."
People who are elderly or in poor health have been given priority to meet the forum panel. Application forms can be downloaded from the website www.hiainquiry.org or requested by calling the inquiry's helpline on Freephone 0800 068 4935.