Philippines. Board of Technical Surveys and Maps. Philippines. Department of National Defense. Sheet 3164 II. Source: U.S. Army Map Series 711. Compiled in 1956 by photogrammetric method using 1947-1953 photographs and others. Transverse Mercator projection. Depths in [meters?]. Relief shown by spot elevation and contour lines at 20 meter intervals with supplementary contours at 5 and 10 meter intervals.