Orientations of churches in Region I, Philippines

Abstract

This study quantitatively assesses the orientations of 36 colonial-era churches in the Ilocos Region (Northwest Luzon) to investigate whether alignments followed liturgical tradition (canonical eastward alignment) or topographical constraints. Using Google Earth and Stellarium, we measured the alignment from altar to entrance for each church. We then compared these headings to both the calculated sunrise azimuth for Easter Sunday in the year of construction and the orientation perpendicular to the nearest coastline. Our findings reveal a high degree of localized consistency in Ilocos Norte and Ilocos Sur, where facades point West-Northwest (284°–302°) toward the sea. By redefining 'coastal' based on the physical visual horizon rather than arbitrary distance buffers, the study demonstrates that approximately 70% of the churches—including those traditionally considered inland—were strategically oriented to maintain a line of sight to the maritime horizon for navigation and defense.