Po Nagar is the biggest tower of the architectural complex that comprises four temple towers built and upgraded several times between the 7^th and the 12^th centuries. The Po Nagar Tower was built by the Cham King Harivacman from 813 to 817. It is two storey-tall, the ground floor being paved with bricks and having many rows of piers and stairs and the upper floor where there are four towers located squarely. The bricks are placed so tightly together that the mortar is almost unseen. The tower entrance faces the east.

The tower's outside has many edges on which there are decorative dome designs, deceivingly making it appear like overlapping towers. The tower body in particular has decorative items such as bas-reliefs and terra-cotta statues symbolizing the Goddess Po Nagar, God Tenexa and fairies, and animals and beasts such as deer, golden geese, lion, etc. The main tower is dedicated to God Shiva's wife, Yan Po Nagar, the goddess of the country.

The Po Nagar Tower has four floors, each has an entrance and in the four corners there are four small towers. Inside the tower, there is a statue of the Goddess made of black granite, 2.6m high, sitting on a lotus-shaped stone base, leaning her back to a large fig leaf-shaped stone plate. The statue is considered a masterpiece of Cham sculpture, a perfect coordination between the statue making technique of polishing and embossing. The other three towers are dedicated to the Indian supreme God of Shiva and his two sons, Gods Sanhaca and Ganeca.

The Thap Ba (Po Nagar) Festival is held annually from March 20^th to the 23^rd of the lunar calendar to highlight the merits of the Goddess who built up the land, kept the race alive, found the rice and taught the local people to farm and make handicrafts. The festival has two parts: the sacrament and the festive activities. The sacramental procedures begin with "changing the dress" of the Goddess, bathing her with perfumed water and dressing her with new clothes. This is followed by worshipping which is implemented very solemnly, praising the merits of the Mother Saint and praying for peace, happiness and prosperity. Performances of dancing and singing, and acting out old stories are held in front of the main tower. Near the ancient tower, beautiful Cham girls seem to come to life from the mystical bas-reliefs, their charming and slender bodies moving and their sun-burnt arms waving to invite visitors back to the origin of the once flourishing Cham Culture.