New memorials marking the sites where dozens of people were murdered in the Dublin bombings of 1974 are to be unveiled today.
The granite stone markers have been placed at the locations where three no-warning car bombs ripped through the capital claiming the lives of 26 people.
Justice for the Forgotten, which represents the victims, will also stage a wreath-laying ceremony at one of the sites in Talbot Street to mark the 34th anniversary of the atrocity.
An anniversary Mass in St Mary's Pro-Cathedral will also remember the seven people killed in a fourth bomb that day in Monaghan.
The explosions during rush hour on May 17, 1974, marked the greatest loss of life in a single day during the Troubles that saw an entire family, including a young father and mother and their two baby daughters, wiped out in Parnell Street.
Relatives of those killed and survivors of the massacre have lodged papers with the High Court challenging key aspects of the recent Government-established investigation, the MacEntee Inquiry.
Justice for the Forgotten said it was reluctantly taking the action after being refused access to evidence gathered in the probe but never published.
The MacEntee Report uncovered a catalogue of failures by the gardai and the Department of Justice including missing files, lax procedures and evidence lost in the aftermath of the bombings.
Investigator Patrick MacEntee SC said it was not possible to fully account for how many files were missing, lost or destroyed from the original garda investigation.
While he could not confirm why the evidence was missing, he refused to rule out unauthorised removal of the documents.
The probe could not substantiate one of the key concerns of the families of the victims that pressure was brought to bear on the gardaí to dump the investigation just three months after it began.