Tay Ninh is situated in the southwest of Vietnam and 95 km north-west of Ho Chi Minh City, sharing a border with Cambodia at the west and the north, and is the original site of Caodaism, Vietnam's most curious indigenous religion. It is from here that Caodaism has spread its influence onto surrounding provokes. In time past, this sect ran its own army, as they had been ruthlessly oppressed by Diem and his regime. The Caodaism followers denied support to the Viet Cong, and after reunification, they were punished for this intransigence by the confiscation of their lands and temples which were not returned to them until 1985.

The eclecticism of the religion is reflected in the colorful Great Temple. Built between 1933 and 1955, it combines architectural elements of a church, a pagoda in an extravagant Rocco style. The cathedral is set within a large complex of schools and administrative buildings painted in pastel yellow. The twin-towered cathedral is of European design, but has distinctly Asian features. On the facade are high-relief figures of Caodai saints, like Victor Hugo, Albert Einstein, etc.

Every day at noon there is a great mass where the tourists are allowed to watch from the balcony.