St. Raphael's is the oldest Catholic church on Kauai. Located amidst former cane fields, the historic church is the result of two major building episodes. The initial, modest structure, built in 1856 under the direction of Father Walsh “along Roman lines,” measured 30 × 45 feet and featured a belfry on its roof. Built of rubble stone, the construction of the building was a labor-intensive task, and the primary materials were of local origin. The coral used to make the mortar was gathered from the reef at Koloa Beach and carried on the backs of parishioners to the church site three miles away.
In 1933 Father Celestine removed the steeple and built the hipped-roof, stone bell tower at the left rear. Three years later, Father Philibert Vanfrachem expanded the church to twice its original size by removing the entrance wall and extending the side walls. The original facade, with its pedimented entrance and round window, was replicated, and new nave windows followed the round-arched design of the old. The integrity of the interior design was also maintained as Tuscan columns were used to support the nave's round-arched arcade, barrel-vaulted ceiling, and roof.
Other buildings of note on the property include the two-story rectory (1856), the parish hall (1939), a chapel (1941), which utilizes a portion of the foundation and walls of an earlier church erected in 1844 by Father Walsh, and the handsome, new church, completed in 1996. The last, designed by James Parsonson of Kauai, represents Hawaiian regionalism in its openness, steep double-pitched hipped roofs with deep overhangs, bamboo-etched glass sliding doors, masonry window screens adorned by a breadfruit motif, and its cloister's lava-rock colonnade. The masonry screen at the altar end window depicts the biblical quotation, “Suffer the little children to come unto me.”