[4] In 1978, through Presidential Decree 1554, the park was reduced to an area of 340 hectares (3.4 km2) concentrated on the lake itself around its highest water level.

[6] It is bounded by the barangays of Suba in the north, Nanguyudan in the northeast, Pasil in the east, Sungadan in the south, and Nagbacalan in the west near the border with the city of Laoag and some 3 kilometres (1.9 mi) away from the sea.

It was formed as a result of coastal progradation and the subsequent development of a sand dune barrier during the late Quaternary Period.

The park is also home to avifauna species such as the white-collared kingfisher, brahminy kite, and Philippine duck, including some migratory birds such as the grey heron, osprey, and great egret.

[6] Also located in the vicinity are Fort Ilocandia Resort and Casino and Plaza del Norte Hotel and Convention Center.