The Hundred Islands National Park is a national park in the Philippines. The protected area is located in the city of Alaminos, in the province of Pangasinan in northern Philippines. The islands, totaling 124 at low tide and 123 at high tide, are scattered in Lingayen Gulf covering an area of 16.76 square kilometres (6.47 sq mi). Only three of them have been developed for tourism: Governor Island, Quezon Island, and Children’s Island. The Lucap wharf in Alaminos, the entrance to the National Park, is about 240 kilometres north of Manila, the capital of the Philippines.
The islands are believed to be about two million years old. They are actually ancient corals that extend well inland, in an area previously comprising the seabed of an ancient sea. The lowering of the sea level have exposed them to the surface. The peculiar “mushroom-like” shapes of some of the islands were caused by the eroding action of the ocean waves.