Zambales lies on the western shores of Luzon island along the West Philippine Sea. Its shoreline is rugged and features many coves and inlets. The Zambales Mountains in the eastern length of the province occupies about 60% of the total land area of Zambales. Subic Bay, at the southern end of the province, provides a natural harbor, and was the location of the U.S. Naval Base Subic Bay until its closure in 1992. (Info from Fast Facts about Philippine Provinces)
Despite its proximity to major cities, Zambales remains the bastion of the Aeta. They were the earliest Filipinos to migrate to the archipelago more than 10,000 years ago – thousands of years even before the Austronesian migration.
Although the Aetas — also known as Ati, Ata, and Agta — are scattered throughout the Philippines, Zambales has the largest known population. (itsmorefuninthephilippines.co.uk)