Region 1, also known as the Ilocos Region, is located in the northwest of Luzon. It borders to the east the regions of the Cordillera Administrative Region and Cagayan Valley, and to the south of the Central Luzon. Located on its west is the South China Sea.
The region is composed of four provinces, namely: Ilocos Norte, Ilocos Sur, La Union and Pangasinan. Its regional center is San Fernando City, La Union.
The cities that make up Ilocos Region are: