Mount Pinatubo is an active stratovolcano in the Zambales Mountains, located on the tripoint boundary of the Philippine provinces of Zambales, Tarlac and Pampanga, all in Central Luzon on the northern island of Luzon. Its eruptive history was unknown to most before the pre-eruption volcanic activity of early 1991. Pinatubo was heavily eroded and obscured from view by dense forests which supported a population of several thousand indigenous Aetas.

Pampanga, officially the Province of Pampanga, is a province in the Central Luzon region of the Philippines. Lying on the northern shore of Manila Bay, Pampanga is bordered by Tarlac to the north, Nueva Ecija to the northeast, Bulacan to the east, Manila Bay to the central-south, Bataan to the southwest and Zambales to the west. Its capital is the City of San Fernando. Angeles City is the largest LGU, but while geographically within Pampanga, it is classified as a first-class, highly urbanized city and has been governed independently of the province since it received its charter in 1964.