Phnom Borei Phnom Da is located in Angkor Borei commune, Prey Kabbas district, Takeo Province. This legend tells why this structure and the temple above it came to be. Once upon a time a mighty king ruled the area of Champassac, or Bassac, in the upper reaches of the Mekong. This king had a daughter, Princess Ak Or, who grew to be the most beautiful woman in the land. But when she fell in love, she fell for a man who was far below her station and their union dishonored the king and all her relatives. The king found out and fell into a rage. He had a raft built and stocked with unhusked rice, husked rice, corns, beans, sesames, salt and prahok (fish cheese) and banished his daughter Ak Or and her lover by setting them adrift on this raft in the river. The raft drifted for a very long time down the river and across a large sea before it ran aground against Phnom Borei, where no one lived. Ak Or and her husband were still in love. They were just grateful to have been washed ashore somewhere which could support them. They planted their crops and built a cottage. They decided they could find everything else they needed to survive by foraging in the forest.
But Ak Or was unhappy. She was homesick and began to regret ruining her reputation. She began to burn incense sticks and candles every night before bed and praying for hours to the spirits, guardians of the mountains and it or forest ghosts, believed to take care of wild animals in the forest and look after the lakes and the hills. She prayed to all these beings for happiness and to provide them with enough to live on. Because prayer is powerful and Ak Or never missed a night, before long she fell asleep and dreamed and the image of an honest man came into her dreams. In her dream, he kept his face obscured, but she heard him clearly. "Do not worry," he told her. "Don't be frightened. I am an honest man who always keeps his promises and I tell you that from today on I am watching over you and will help you. You will grow famous and wealthy in this place. But I will not reveal my face to you." As soon as he left her dream, she woke up and told her husband straight away, who was worried for her and filled with pity that she was so upset.
From that day, she had her husband go into the forest to find wood for their fire. The husband happily cut wood from a sweet smelling tree which grew there in abundance. He put it in neat piles to be burned. One day, Ak Or went to see how their wood supply was going, and was overjoyed, for she knew as soon as she saw it that all the wood was valuable sandalwood. But she didn't let on to her husband about her discovery, only smilingly telling him to work harder as they must have more wood.
Ak Or's husband loved her very much, so he tried to please her. He went deeper into the forest, and one day there, he saw bright rocks lying on the ground which were different to any rocks he had ever seen before. "These are pretty," he told himself, "I will take three of them for my wife in order to set up a fireplace." The man took those rocks and put them in small shallow basket and carried them home. When his wife saw them, she knew immediately that they were gold, but she did not tell her husband, saying only: "These are so beautiful! If you see this kind of rock again, please bring them all home." The husband always took her advice. He began bringing home chunks of gold along with bundles of sandalwood. One day, the princess decided they were ready. The gold and precious wood was piled high. "Now I think I can place a high flag as a sign. There may be ships sailing from other countries that will see it and come to buy from us."
The ships came, the couple grew rich and famous, and within a few years, other settlers came to join Ak Or and her husband. They themselves lived long and happily, producing many children and grandchildren. Villages and districts developed, and all of these people loved Princess Ak Or and her husband, who took the throne to rule over the land with his wife under the name Preah Bat Songkh Chak. The royal couple constructed a huge fort out of bricks and stones and called its ramparts Da. The word Da means Rock. Since then the mountain has been called Phnom da (Rock Mountain) until this day. When they had finished their walled city, Preah Bat Songkh Chak and Queen Ak Or ordered their subjects to build a small but beautiful stone temple on the eastern top of the mountain to pay tribute to the honest man who had kept his promise and redeemed Ak Or's honor. That temple is called Prasat Phnom Da and stands to this day. And that is the legend of Phnom Borei Phnom Da .