Travelers from all over the world shared cherished memories of their visits to one of the most beloved religious structures in the world with CNN. Here are their stories.
"We did not know this would be her last trip," Hilts said. Her mom died in 2003.
Hilts said her mom's back was bothering her, so she waited on the bench while she went inside to light a candle.
"My memories of this beautiful sanctuary, especially the windows and statues, are embedded forever and intertwined with my love for her," Hilts said.
Catherine Furey, 24, Pennsylvania, is a devout Catholic who's been to church almost every Sunday since she was a baby.
She said going to Mass at Notre Dame Cathedral as a college student in 2014 made her beliefs even stronger.
"The Mass was in French, and all of the tourists attending spoke different languages. We all followed along and replied in our own languages. It was extraordinary," Furey said.
Seeing the Crown of Thorns, which some believe was placed on the head of Jesus during the crucifixion, gave her the overwhelming feeling that "Wow, this is real."
"As soon as they took the cover off the crown, I wept and was filled with an immense feeling of love and gratitude for the sacrifice on the cross," she said. "I have never doubted my faith since that day."