Tay Ninh province, 94km northwest of Ho Chi Minh City, is bordered by Cambodia on three sides. Its famous for the Ba Den (Black Lady) Mountain, a place of pilgrimage of the Mekong Delta population and Caodaism, an indigenous religion existing only in Vietnam founded in 1927 from a very striking idea: the fusion of all world main religions into one.

Black Lady Mountain, 10km northeast of Tay Ninh, rises 986m above the rice paddies of the surrounding countryside. It is an historical and beautiful site covering an area of more than 24km2. Over the centuries, the name Black Lady Mountain derived from the legend of Ly Thi Thien Huong, a beautiful woman who was forced to marry the son of a rich mandarin while her true love was away doing military service. But preferring death to dishonor, she threw herself off a cliff. She then reappeared in the visions of a monk living on the mountain.

The Holy See of Cao Dai serves as the headquarter of one of Vietnams most interesting indigenous religions, Caodaism. It is 4km east of Tay Ninh, built between 1933-1955. Prayers are conducted in the Great temple everyday at 6 a.m., noon, 6 p.m. and midnight.