The Prince's Castle is a general area consisting of a group of hills, the beach, the Cham towers, a pagoda, a famous poet's tomb (Nguyen Thong), and specifically the ruins of a large French estate. The hills are situated in the Phu Hai district of Phan Thiet and offer the best view of the city, rivers, mountains and beach within the valley. The temple hill is across the street from the city's main cemetery (a virtual necropolis), where the poet's tomb is located.

In 1911, a French prince as well as Duke De Montpensier came to Phan Thiet for traveling and hunting. He admired this beautiful spot so much that he decided to buy a plot of land here and build a villa. The French authority in Binh Thuan (Ambassador Gamier) agreed to sell him Ba Nai Hill. On the 21st of February, 1911 ground was broken and the estate completed nearly one year later, with a total area of 536 sq.m. and 13 rooms. The villa was built 100 meters South of the Cham tower temple group. In the process of the villa construction, the French destroyed the wall in front of the Tower's main door. This estate had electric generators at night and cisterns to store water, this villa was considered to be the most modern structure in Binh Thuan at that time. Locals have refered to the area as "The Price's Castle" since.

Located on Ong Hoang (Mr. Heaven) Hill and built in the late 8th century, the Thap Poshanu Cham Tower worships god Shiva, who is highly venerated by the Cham. Beside these three towers there was once a temple, but it has been buried for more than 300 years. Inside the main tower is an altar, on which a couple of Liga-Yoni (a symbol of Shiva) is worshipped. The towers were repaired and upgraded from 1990 to 2000.

Fishermen living in the vicinity also come here to appeal for safe sea journeys before they go out to sea. The are sometimes refered to as the castle of the king and queen (or god and godess) of the sea. Much local folklore and legend has developed regarding the towers, since the time they were built by the anchient Cham people. the towers have served as an important landmark for fishermen and shipping vessels in navigation as well.
It should be noted that on the same hill with the Cham temple complex is a former military stronghold from the recent war. While the Towers are safe to explore, we recommend visitors do not climb around the nearby fort due to the possibility of unexploded ordinences.