Façade of St Paul's Cathedral

St Paul's Cathedral (Chinese: 聖保祿大教堂, commonly known as "大三巴") was a 16th-century cathedral in Macau, China. Today, its ruins are arguably the Macau Region's most famous tourist site.

Built from 1582 to 1602 by the Jesuit priesthood, the Cathedral was the largest Christian church in Asia at the time, and the royalty of Europe vied with each other to bestow upon the Cathedral the best gifts. With the decline in importance of Macau, which was overtaken as the main port for the Pearl River Delta by Hong Kong, the Cathedral's fortune's similarly ebbed, and it was destroyed by a fire during a typhoon in 1835.

The ruins now consist of the southern stone façade - intricately carved by Japanese monks - and the crypts of the Jesuits who established and maintained the Cathedral. The façade sits on a small hill, with 66 stone steps leading to the façade. The carvings include Jesuit images with Oriental themes, including one of a woman stepping on a seven-headed hydra, described by Chinese characters as 'the Holy Mother tramples the heads of the dragon'. Other engravings include those of the founders of the Jesuit Order, the conquest of Death by Jesus, and others, all topped by a dove with wings outstretched.

Resisting calls for the dangerously leaning structure to be demolished; from 1990 to 1995 the ruins were excavated under the auspices of the Instituto Cultural de Macau , to study its historic past. The crypt and the foundations were uncovered revealing the architectural plan of the building. Numerous religious artifacts were also found together with the relics of the Japanese Christian martyrs and the monastic clergy, including the founder of the Jesuit college in Macau, Father Alessandro Valignano. The ruins were restored by the Macanese government into a museum, and the facade is now buttressed with concrete and steel in a way which preserves the aesthetic integrity of the facade. A steel stairway allows tourists to climb up to the top of the facade from the rear. It is customary to throw coins into the top window of the ruins from the stairs, for luck.

The Fortaleza do Monte overlooks the ruin.