Quirino in the context of Cabarroguis, Quirino

Cagayan Valley (Ilocano: Tanap ti Cagayan; Filipino: Lambak ng Cagayan; Spanish: Valle del Cagayán), designated as Region II, is an administrative region in the Philippines. Located in the northeastern section of Luzon, it is composed of five Philippine provinces: Batanes, Cagayan, Isabela, Nueva Vizcaya, and Quirino. The region hosts four chartered cities: Cauayan, Ilagan, Santiago, and Tuguegarao (the regional center and largest city).

Most of its land area lies in the valley between the Cordilleras and the Sierra Madre mountain ranges. The eponymous Cagayan River, the country's largest and longest, runs through the region, flows from the Caraballo Mountains, and ends in Aparri. Cagayan Valley is the second-largest Philippine administrative region by land area. According to a literacy survey in 2019, 93% of Cagayan Valley's citizens (ages 10 to 64) are functionally literate, which is 5th out of the 17 regions of the Philippines.

Aurora, officially the Province of Aurora (Tagalog: Lalawigan ng Aurora; Ilocano: Probinsia ti Aurora; Spanish: Provincia de Aurora), is a province in the Philippines located in the eastern part of Central Luzon region, facing the Philippine Sea. Its capital is Baler and borders, clockwise from the south, the provinces of Quezon, Bulacan, Nueva Ecija, Nueva Vizcaya, Quirino, and Isabela. Maria Aurora is the only landlocked town in the province and yet, the most populous. It is the only province in Central Luzon that has no chartered cities.

Before 1979, Aurora was part of the province of Quezon. The province was named after Aurora Aragon, the wife of Manuel L. Quezon, the president of the Philippine Commonwealth, after whom the mother province was named.

The Cagayan River, also known as the Río Grande de Cagayán, is the longest river and the largest river by discharge volume of water in the Philippines. It has a total length of approximately 505 kilometres (314 mi) and a drainage basin covering 27,753 square kilometres (10,715 sq mi). It is located in the Cagayan Valley region in northeastern part of Luzon Island and traverses the provinces of Nueva Vizcaya, Quirino, Isabela and Cagayan; it also flows through the only Central Luzon province of Aurora.

Nueva Vizcaya, officially the Province of Nueva Vizcaya, is a landlocked province in the Philippines located in the Cagayan Valley region in Luzon. Its capital and largest town is Bayombong. It is bordered by Benguet to the west, Ifugao to the north, Isabela to the northeast, Quirino to the east, Aurora to the southeast, Nueva Ecija to the south, and Pangasinan to the southwest. Quirino province was created from Nueva Vizcaya in 1966.

Isabela, officially the Province of Isabela (Ilocano: Probinsia ti Isabela; Ibanag: Provinsia na Isabela; Tagalog: Lalawigan ng Isabela), is the second largest province in the Philippines by land area located in the Cagayan Valley. Its capital and the largest local government unit is the city of Ilagan. 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, Aurora and the independent city of Santiago to the south, and the Philippine Sea to the east.

This primarily agricultural province is the rice and corn granary of Luzon with its mix of plains and rolling terrain. In 2012, the province was declared as the country's top producer of corn with 1,209,524 metric tons. Isabela was also declared the second-largest rice producer in the Philippines and the "Queen Province of the North".

Santiago, officially the City of Santiago (Ilocano: Siudad ti Santiago; Ibanag: Siudad nat Santiago; Gaddang: Siudad na Santiago; Filipino: Lungsod ng Santiago), is an independent component city in the Cagayan Valley region of the Philippines. According to the 2024 census, it has a population of 150,313 people.

It is formerly known as Carig during the time of the Spanish, it is located between the southwestern part of Isabela and the northwestern boundary of Quirino in northeastern Luzon island of the Philippines. It is the gateway to the vast plains of Cagayan Valley.