In 1690, Oslob became a visita of Boljoon which had been raised to an independent vicariate (parish). From 1737-42, because of personnel shortage, the Augustinians handed the administration of Oslob to the Jesuits. Oslob became an independent parish in 1848 (1847 according to some authors) under the advocacy of the Immaculate Conception. It had one visita, Tañon (present day Santander). Fr. Julian Bermejo is credited with building the church, laying its foundation on 4 May 1830. The plans were drawn by Cebu bishop Santos Gómez Marañón. Completed 18 years later, it was blessed by Bp. Romualdo Gimeno in 1847. Fr. Apolinar Alvares built the adjacent bell tower in 1858. Although Fr. Julian started construction of the convent, it was finished and reinforced with buttresses by Fr. Juan Aragones between 1848 and 1850. Fr. Juan was later appointed bishop of Nueva Segovia (Vigan). Fr. Gregorio de Vela installed eleven bells at the bell tower in 1894, but when its fifth story was damaged, he transferred the bells to the fourth story. He also repaired the floor, added altars at the transept, restored the main altar, improved the sacristy and added a small pipe organ. Fr. Mauricio Alvarez not only rebuilt the damaged bell tower but set about to improve the layout of the town, the cemetery and the streets. In 1932, Fr. Pablo Alva replaced the church's tile roof with galvanized sheets. The church was burnt during the war, and subsequently the vault and dome fell. Again the church was gutted in 1955, Fr. Benedicto Zapra restored the church, restoration continued under Fr. Constantino Batocoy and was completed in 1980.

The church complex is surrounded by a wall and outside of it, by the shore, are the remnants of a watchtower.

Heritage Features: The church and convento use cut coral blocks. The Classical lines of the church are accentuated by six two-story tall pilasters. The pilasters' vertical sweep harmonizes with the rectangular fenestration of the second story but contrast with the tall semi-circular opening of the main entrance. The plain triangular pediment crowned with pointed finials is separated from the rest of the façade by Classical dentils. The harmony and contrast of the façade is echoed by the bell tower where rectangular windows mark the first two story and arched window (some open others blind) the third and fourth. The bell tower is octagonal with diminishing dimensions at the upper stories. The convento built at the side of the church is an oversized bahay na bato.

Santander

San Gabriel Archangel Parish

Established in 1898, this was the southernmost visita of the Augustinians. Its ancient name was Tañon or Tanong which gives its name to the narrow but deep strait between the islands of Cebu and Negros.

Along Santander's coast, Fr. Julian Bermejo built four watchtowers to guard the strait and the entrance to the coastal towns of Negros. Complementing these towers, on Negros island are other watchtowers, remnants exist in Dauin, south of Dumaguete, and Dumaguete's detached bell tower is itself a watchtower.

Samboan

San Miguel Arcangel Parish

Established as a parish in 1784, the church was probably built by the secular clergy, as the Augustinians have no record of building a church at Samboan. Samboan was a visita of Tanjay in Negros. The dates for the church building are uncertain. Sited on a plateau overlooking the Tañon Strait, the church complex has a three story watchtower facing the sea. This simple open structure has openings on all four sides, and an archway on the lower story leads to a flight of stair leading to the foot of the hill. This stairway is popularly called "Jacob’s ladder." Although the Neoclassic church has a well preserved façade and interior, it appears commonplace in contrast to the watchtower at the head of "Jacob's ladder" and overlooking the Tañon Strait. The tower is somewhat run down but it is still possible to climb to the second story where the vista is stunning. From the Negros side, Samboan's whitewashed watchtower can be clearly seen, thus, betraying its function as a guardian of the Tañon Strait and the coastal towns east and west of it.