Once upon a time, there was a place called the Forest of the Giants. One day, an impoverished man abandoned his 12 infant daughters in the forest because he could not support them. A giantess called Neang Santemea found them there and took them to her daughter Neang Kong Rei to be her servants. The little girls' lives were hard and eventually they managed to escape to a neighboring kingdom where the king saw them and declared he would marry all 12 at once. But Neang Santemea found out where the girls had fled and how happy they were in their newfound wealth. She disguised herself and used her charm to make Rothasith fall in love with her and make her his thirteenth wife. Meanwhile, all twelve sisters fell pregnant.

But Neang Santemea was not to be beaten. She feigned a deadly illness none of the king's physicians could cure. Her grief-stricken husband fell under her spell and listened when she told him the only cure for her illness. "Only a potion made from 23 eyeballs of pregnant women will cure me," she wept. The king ordered the eyes of his 12 first wives removed to save his last wife. Only one, the youngest sister Neang Peov, was allowed to keep one eye. Then the mutilated women were confined to a cave and forced to eat their newborn children one by one. Only Neang Peov managed to save her son Puthisen. In Khmer, the boy's name means "very knowledgeable". The miraculously cured Neang Santemea grew more and more nervous as Puthisen grew into a young man. She feared he would become king. She wrote him a letter and asked him to take his horse and ride into the neighboring kingdom. "This is a letter of passage through the Forest of Giants," she told him. In fact, it was a message to the guard giants telling them to kill and eat the young man as soon as he arrived. Puthisen rode off to the Forest of Giants.
On the way he met a hermit who told him what the letter said. "But I can change it. Here, now you will be safe," the hermit told Puthisen. When Puthisen arrived the giants greeted him and read the note. "Ah, Neang Santemea says you must be married to her daughter," they cried. So Puthisen married Neang Kong Rei. Neang Kong-Rei fell deeply in love with him on sight, not knowing he was her mother's mortal enemy. As soon as Puthisen could, he found out where the giants were keeping the eyes they had taken from the 12 sisters and stole them back, then leapt back on his horse to ride home and return them. Neang Kong-Rei knew she could not live without him and tried to stop him, but he used a magic potion to turn the land between them into water so she could not follow. Neang Kong-Rei cried herself to death, and her body turned into the mountain of Kong Rei, which lies across the river in Kampong Chhnang and still resembles the body of a prone woman. And that is the story of Neang Kong-Rei Mountain.