Po Nagar is a Cham temple tower founded sometime before 781 and located in the medieval principality of Kauthara, near modern Nha Trang in Vietnam. It is dedicated to Yan Po Nagar, the goddess of the country, who came to be identified with the Hindu goddesses Bhagavati and Mahishasuramardini, and who in Vietnamese is called Thiên Y Thánh Mâu.
A stele dated 781 indicates that the Cham King Satyavarman regained power in the area of "Ha-Ra Bridge", and that he restored the devastated temple. From this inscription can be deduced that the area previously had come under temporary foreign dominion, and that foreign vandals had damaged the already existing temple.
Other steles indicate that the temple had contained a mukhalinga decorated with jewelry and resembling an angel's head. Foreign robbers, perhaps from Java, "men living on food more horrible than cadavers, frightful, completely black and gaunt, dreadful and evil as death" had arrived in ships, had stolen the jewelry and had broken the linga. Though the king had chased the robbers out to sea, the treasure had been lost forever. The steles also indicate that the king restored the linga in 784.
A stele dated 918 by the Cham King Indravarman III states an order to build a golden statue to the goddess Bhagavati. Later steles report that the original statue was stolen by the Khmer, and that in 965, the king replaced the lost statue with a new one. A stele dated 1050 says that offerings of fields, of slaves, of jewelry and of precious metals were made to the statue. Later steles indicate the celebration of a cult in honor of the goddess Yan Po Nagar, as well as the presence of statues dedicated to the principal deities of Hinduism and Buddhism.
The Po Nagar complex is situated on Cù Lao Mountain. It consists of three levels, the highest of which encompasses two rows of towers. The main tower is about 25 m high.