What is the largest plain in Philippines?

The largest plain in the Philippines is the Central Plain, also known as the Central Luzon Plain. It covers an area of approximately 11,500 square kilometers (4,400 square miles) and is located in the northern part of the country, in the region of Central Luzon. The Central Plain is bounded by the Sierra Madre mountain range to the east, the Zambales Mountains to the west, the Caraballo Mountains to the north, and Manila Bay to the south. The plain is drained by the Pampanga River and its tributaries, and the land is fertile and suitable for agriculture. The plain is home to several cities and municipalities, including the cities of Manila, Quezon City, and Caloocan.