Agnigrah is a hill top garden with murals from Mythology about the legend of Usha's abduction of Aniruddha, the grandson of Krishna and the ensuing battle by Krishna to free them. The park also has a tall viewing platform from where the entire Tezpur town can be seen on one side while on the other side the Koliabhomora Bridge which spans across the vast Brahmaputra River.

Legend has it that the Banasur king of Sonitpur had this fortress built so that no one could enter or leave without his permission and surrounded the fortress by fire at all times. His daughter Usha fell in love with Aniruddha Grandson of Lord Krishna, in her dreams, and asked her companion Chitralekha to paint his portrait through her verbal description. Chitralekha was not only an artist but one blessed with mystical powers. She flew one night and brought Aniruddha to Usha's place while he was in his sleep, using her powers, upon waking up Aniruddha saw Usha, he fell in love immediately. On hearing this news King Banasura became furious, and asked his army to tie Aniruddha with snakes and imprisoned. However, Lord Krishna had agreed for this union and asked for Banasura’s consent for the same, to which he promptly declined. Lord Krishna was very angry at King Banasur’s refusal and along with his brother Balram marched on to Sonitpur.

As a great devotee of Lord Shiva, Banasura had a boon where Lord Shiva which made him invincible, therefore he was not at all scared by Lord Krishna's wrath. Soon this war took shape of war between the Hari (Lord Krishna and his followers) and the Hars (Lord Shiva and his followers), thousands were killed from both the sides starting rivers of blood which gave the city a new name - Tezpur (City of Blood). Lord Brahma had to intervene as the war had reached apocalyptic proportions, with both Hari and Har facing each other Lord Krishna made Lord Shiva see how Banasura had wronged by making Lord Shiva the gate keeper of Sonitpur and imprisoning his grandson. Lord Shiva understood and made Banasura agree to the marriage.