The Missing Persons national monument in Kilkenny Castle was unveiled by then President Mary McAleese 21-years ago today (Saturday).
The monument, which features the handprints of family members of the missing, was commissioned by a trust established by the late Mary Phelan, from Callan, Co Kilkenny, whose sister, JoJo Dullard, has not been seen since November 1995.
The anniversary is being marked by a special event in the castle grounds tomorrow (Sunday).
People are advised to meet at the entrance to Kilkenny Castle at 11:30am to walk to the monument where there will be prayer and reflection, music by Kilkenny Gospel Choir and an address from Minister Simon Harris.