In Hindu Dharm, there are many holy places, such as Allahabad, Kaashee, Badare Naath, Kedaar Naath, Haridwaar etc etc. Gayaa is one of them and is mostly famous for Pitri Tarpan and Shraaddh. Why Gayaa is such a big Teerth? Gayaa, situated in Bihar State, is one of the very big and important Teerth (pilgrim place, or holy place) for Hindu. Why is it so? There is an interesting legend behind it.
In one of the previous Manvantar, Dharm had his wife named Dharmvatee. They had a daughter named Dharmvrataa. Dharm married her to Brahmaa's mental son Mareechi. Once Mareechi was very tired so he came home and asked his wife to massage his feet. She started massaging his feet. He felt so comfortable that he soon slept. In the meantime Brahmaa Jee came there. Now Dharmvrataa was in a flux that she should serve her husband or her father-in-law. She decided that since her husband had already slept, and Brahmaa Jee was her father-in-law, she might serve him now, so she got up and served Brahmaa Jee.
In the meantime Mareechi got up and did not find his wife around. He cursed her to become a stone. Dharmvrataa said to her husband - "Since you have cursed me without any fault, you will be cursed by Shiv." She kept aside Muni's curse and entered fire. Then she performed penance and all Devtaa bestowed her a boon - "Maharshi's curse cannot be averted, you have to be a stone, but we will have our footprints on you so you will become the holy stone. There is a Raakshas named Gayaasur. your stone will be used to stabilize his body. At that time you will be called by the names of Dev-Shilaa, Devavrataa, Sarv Dev Swaroopaa." Dharmvrataa said - :Then grant me one more boon, that after I have become stone all Devtaa and Devee should live in me." "So be it." and all Devtaa went away.
Now there was a Raakshas named Gayaasur. Once he performed severe penance and obtained the boon of being the holiest Teerth among all the Teerth. Bhagavaan granted this boon to him and disappeared. Now since he was the greatest Teerth, so all people came to him for his Darshan. Prithvi became empty, as all the people came to see him and went straight to Vishnu Dhaam after his Darshan, so Brahmaa Jee and all Devtaa went to Vishnu and told their saga. Vishnu Jee suggested them to go to Gayaasur and ask his body to be used for Yagya, so Brahmaa Jee and Devtaa went to Gayaasur and asked his body to perform a Yagya. Gayaasur considered it a holy act so he agreed.
Brahmaa Jee started a Yagya on his forehead. When the time came for Poorn Aahuti, his body started trembling. Brahmaa Jee again went to Vishnu and said to Him - "At the time of Poorn Aahuti, Gayaasur's body was scared and it was trembling, how to complete the Yagya?" Vishnu called Dharm and asked him to keep that Dev Shilaa on Gayaasur's body to stabilize it and asked all Devtaa to sit upon it. Still his body did not get stabilized. Then He kept His own Gadaadhar idol on the stone along with Devtaa, then only his body got stabilized. Brahmaa Jee completed his Yagya by offering the Poorn Aahuti.
After the Yagya, Gayaasur asked Devtaa - "Why did you need to put a Shilaa (stone) over me to stabilize my body? Couldn't be stabilized just by the words of Vishnu? Since you pressed my body with a stone, now you bestow me a boon." Devtaa said - "We just pressed your body with the stone only to make Teerth, that is why it will be a dwelling place for Vishnu, Brahma and Shiv. It will be more famous than other Teerth and it will give Brahm Lok to Pitar." After saying this all Devtaa started living there. Vishnu also always lives there in His Gadaadhar form. That is why Gayaa is the holiest Teerth among all the Teerth.
That is why Gayaa is the holiest Teerth among all the Teerth.