Phat Diem Cathedral was built between 1875 and 1899 four roofs and six sets of iron wooden pillars and consists of a network of ponds, lakes, churches, and artificial caves.

Phuong Dinh Church, part of the Phat Diem complex, is a giant building entirely made of stone. Numerous stone sculptures are on the inside and outside walls. A large bell cast in the 1890s weighing nearly 2 tons is found in the bell tower.

On both sides of the church are four smaller churches of different styles. On the extreme north corner are three stone caves. The most beautiful of these caves is Lo Duc Grotto. In the area surrounding this massive stone and wood cathedral, the rice paddies are peppered with stone churches. But, unlike these structures, built by Europeans and resembling typical churches of the era, Phat Diem Cathedral was designed by a Vietnamese priest, known as Father Sau. Father Sau rallied the local population to build the cathedral, five side chapels, three artificial grottoes, an artificial lake and a bell tower. Phat Diem Cathedral seems to have changed very little since Graham Greene described its gigantic pillars formed out of single trees and the scarlet lacquer work of the altar. Indeed, with its multi tiered, curling roofs and its 48 lime-wood columns - (the largest of which weigh seven tones), Phat Diem is a far cry from a European cathedral. Stone relief angels overlook carved dragons and the cathedral's two-tone bell is accompanied by a giant brass gong.

Local Catholics view the cathedral's survival as almost miraculous; a bombing in 1972 flattened two of the side chapels and caused the cathedral to lean by some 20 degrees. Despite the ongoing war, restoration started immediately and today, the only obvious trace of the bombing is the destruction of some intricate stone carvings. And on Christmas Eve, an unforgettable midnight mass, attended by thousands and accompanied by a brass band, is held in the cathedral grounds.