Luzon Datum is a geodetic reference center located in Mogpog in Marinduque Province. During the American occupation, the United States Coast and Geodetic Survey (USCGS) use the Luzon Datum of 1911 to get information for topographic, geodetic and hydrographic surveys. This important geodetic point marker is used as point number one for all map makers of the country. Luzon Datum was established with triangulation station Balanacan as its datum origin and now the primary geodetic reference center of all surveys in the Philippines. Luzon Datum marker is found atop of the highest hill in the province, and is at the bounderies of Brgy. Argao, Hinanggayon and Silangan, Mogpog.