SAN ISIDRO, ē̇-sē′drō̇. The capital of the Province of Nueva Ecija, in Luzon, Philippines (Map: Philippine Islands, E 4). It is situated on the Rio Grande de la Pampanga, 48 miles north of Manila, has a telegraph station and good road connections with Manila and other cities of Central Luzon. Population (estimated), in 1899, 7056.