Po Nagar Tower
The Po Nagar Tower was built by the Cham people, an Indochinese culture that practices Hinduism. You can see some of the Indian influence in the architecture of this temple, which was completed sometime in the 13th century.
Po Nagar is a Cham version of a female Hindu deity. There are smaller temples around the main tower that are dedicated to other Hindu deities and contain the traditional male and female symbols of lingam and yoni. After the Vietnamese took over this area in the 17th century, they rededicated these temples to deities from their own tradition, and the goddess Po Nagar was usurped by Thien Y A Na and her husband.
Po Nagar is a common day trip for visitors staying in Nha Trang. If you do visit, keep in mind that temple visits require modest dress. The temple can provide you with a robe if you arrive in summer-y attire.