San Agustin is about twelve kilometers west of the town proper. It is bounded on the north by Sulipa, on the east by Santiago, on the south by Calayaan, and on the west by the Bimmaribar forest, San Agustin is heavily wooded. It is of broken topography. It is hilly and sloping.

Formerly known as Visay which one of Sulipa, San Agustin comprises the sitio of Likod, Buritrit, and Bummaribar. It was christened by Pastor Anastacio Ortiz of the Methodist Church. Most of the people in this place are Protestants. This barrio and named after the first Barrio Lieutenant, Mr. Candido Agustin, Raymundo Bacnis, Catalino Madriaga, and Pedro Pascua. 


1. Candido Agustin
2. Pedro Pascua
3. Isaiac Gregorio 

During the Spanish regime, it was common among low breakers who did not want to pay tribute to make this barrio their hiding places. The barrio was the place. The barrio was the place where the katipuneros camped.

During the American occupation, the barrio inhabitants led a happy and peaceful life because there was not only peace and order, but also there was abundance in foods. It was popular to the guerillas during the Spanish, Japanese occupation because of its terrain favorable to guerillas activities. The people of the barrio still observe the customs and traditions of their ancestors. Courtship and eventual marriage of parties are done through parental intervention.