Kalinga-Apayao was a province of the Philippines in the Cordillera Administrative Region in the island of Luzon. It was divided into the two provinces of Kalinga and Apayao with the passage of Philippine Republic Act No. 7878 on February 14, 1995. This RA amended the earlier Republic Act No. 4695, passed on June 18, 1966, which formed the provinces of Kalinga-Apayao, Benguet, Ifugao, and Mountain Province, from the earlier Mountain Province. Its boundaries were called the "great profile" due to the resemblance to the head of former president Ferdinand Marcos whom approved the formation of that province.
Read more about Kalinga-Apayao: History