In September 1979, a couple of weeks after an IRA bomb had shattered the peaceful beauty of Mullaghmore, killing her son, Mary Hornsey made a poignant return to the village.
She gazed across its scenic headland, over the calm waters of Donegal Bay, and whispered goodbye.
It was a visit filled with emotion, for she realised it would be the last one.
"It was extremely painful, because I knew I wasn't going to go there any more," she recalled this week.
Once this sleepy west coast fishing village was a place of happiness. Since that terrible August bank holiday 36 years ago, however, it stirs only pain and heartache for a mother still grieving for her lost boy.
Mary knows only too well the emotions which will confront Prince Charles when he visits Ireland next week.
The heir to the throne's itinerary includes a stop-off in Mullaghmore, where his great uncle Lord Mountbatten was assassinated by the IRA.
The 79-year-old, a mentor to the Prince, died on August 27, 1979, when a remote-control bomb blew apart his boat, the Shadow V. On board were three generations of family members and Paul Maxwell, a 15-year-old schoolboy from Enniskillen. Paul was killed instantly along with Mountbatten.
Paul's mother, who later remarried, said the family had been visiting Mullaghmore for about 10 years previously. However, she recalled how she was never quite won over by its scenic charm.
"We had a little cottage in Mullaghmore and from the outset I never liked it. I don't know why," she remembered. "I wasn't keen on it at all, but other family members thought it would be a good thing to have it.
"That summer of 1979, in August especially, I could sense there was an aura of, like, evilness, or something not right. I could sense that.
"It was like I had a dream of awful things happening and I don't usually have dreams like that."
Mullaghmore was a popular spot for families, and also with Lord Mountbatten, the last Viceroy of India and a decorated war hero.
He spent his summers at Classiebawn Castle, a towering 19th century structure which dominates the surrounding area.
The explosion happened around 11.30am on a beautiful, sunny morning. As the Shadow V set off for a fishing trip off the coast, it was destroyed by a 50lb radio-controlled bomb.
Paul Maxwell, Lord Mountbatten and the earl's 14-year-old grandson Nicholas Knatchbull were killed.
The Dowager Lady Brabourne, mother-in-law to Mountbatten's elder daughter, died of her injuries the next day. Lord and Lady Brabourne, Nicholas's mother and father, and his twin brother Timothy, all survived the explosion but were seriously injured.
Nearly 36 years later the memories of that day remain painfully vivid for Mrs Hornsey.
"On that morning, the 27th of August 1979, Paul said 'goodbye mum', as he always did," she recalled.
"He gave me a kiss and he set off to go to Classiebawn where he would go down to Shadow V with Lord Mountbatten and the entourage."
That was the last time she saw her son alive. Minutes later the sound of the explosion shattered the peace and tranquillity.
Mary recalls how she immediately feared the worst. "I was sitting on the patio at the back with my daughter and Paul's father. It was a really beautiful day. The weather had been dreadful that August. Nothing but rain, rain, rain. And then, on that day, it was the most fantastic day. The sun was shining and we could hear the skylarks singing once again.
"And as we sat, there was one almighty bang, and immediately I knew. I said 'It's Paul, Paul is dead'. My husband said: 'Don't be so silly'. We didn't know what had happened, but I knew Paul was dead.
"Paul's father rushed down to the harbour and he found out what had happened. Paul was dead. He was killed instantly.
"I didn't know that morning when I said goodbye to Paul that that would be the very last time I would see him alive. It's awful to think that the next time I saw him he was in his coffin."
Paul's parents parted after their son's death. His father John still lives near Enniskillen and became a passionate supporter of integrated education. Mary, meanwhile, remarried and moved away.
She took solace in writing poetry, but says the passage of time has failed to lessen the pain. "It's always there, always, always there," she added.
More memories are stirred as she flicks through photographs. One is a black and white image of Paul, and the twins Nicholas and Timothy, which, she explains, was taken on Shadow V before the explosion.
Incredibly, the camera was found in the water and the image survived.
Another is of a group of 21, including Lord Mountbatten and Paul, taken outside Classiebawn Castle.
Only once, a couple of weeks after the explosion, did Mary return to Mullaghmore. "I went round to the headland where it all had happened, and I threw some flowers there, some roses, and I said goodbye," she recalled. "I have never gone back since."
Nor has she any desire to go there in the future.
"I have never thought of going back," she said. "I don't think I really have any desire to go back again because so much pain happened there."
Next week's royal visit has placed Mullaghmore in the spotlight once more, reviving memories of a dark segment of the past that its residents would rather forget. But for Mary, the heartache and anguish has never gone away.
"There always is pain there," she said. "As I said in one of my poems, I laugh and smile again with sadness in my eyes - that's how it's always going to be. Always. To the day I die.
"I think most mothers who have lost children will feel like that as well. You go on, but with a great sadness always there. A big gap."