The Our Lady of the Pillar Parish Church is located in Cauayan City in the province of Isabela. The story of the church traces back to September 1739, when Dominican missionaries first arrived in the area and established the settlement that would later be known as Cauayan. By 1741, the mission had grown into a full-fledged parish under Dominican administration, and it was placed under the patronage of Nuestra Señora del Pilar, from whom the church derives its name.

The construction of the present church structure began much later, in 1825, under the supervision of Fr. Juan Prieto, O.P., and was completed in 1830. Built primarily using stone, mortar, and bricks, the church reflects the durability and craftsmanship typical of Spanish colonial ecclesiastical architecture in the Cagayan Valley. Its most recognizable feature is its red brick façade, often associated with what locals describe as “Tuguegarao-style” Baroque architecture, a regional adaptation characterized by solid brickwork and simple but imposing lines.

Like many heritage churches in the Philippines, Cauayan Parish Church endured significant damage during the Second World War. Large portions of the complex, including the convent, were destroyed and required full reconstruction. Despite this, parts of the original Spanish-era structure survived, particularly sections of the façade and the base of the bell tower, which remain as tangible links to its 19th-century origins.