Isabela is the second largest province of the Philippines, and the largest on the island of Luzon in land area. Its capital is the city of Ilagan. Situated within the Cagayan Valley region, it is bordered by the provinces of Cagayan to the north, Kalinga to the northwest, Mountain Province to the central-west, Ifugao and Nueva Vizcaya to the southwest, Quirino and Aurora to the south, and the Philippine Sea to the east. This primarily agricultural province is the rice and corn granary of Luzon due to its plain and rolling terrain. In 2012, the province was declared as the country’s top producer of corn with 1,209,524 metric tons. Isabela is the 10th richest province in the Philippines as of 2011. The province has four trade centers in the cities of Ilagan, Cauayan, Santiago and the municipality of Roxas.