Mount Natib complex starts from Dinalupihan and end in Balanga City. Mount Natib complex is made up of Mount Santa Rita (485 m.) and Mount Santa Rosa (800 m.) on the east, Mount Silangan (910 m.) on the south.

Marivels Mountain begins from Pilar and ends in Mariveles. It is constituted of Pantingan Peak (536 m.) on the north, Orion Peak (465 m.) and Mount Limay (946 m.) on the east, Mount Mariveles (1,388 m.) on the west,and Mount Alas-asin (406 m.) on the south.

Photo by Avegale Rito & Rio Sebastian.

The well-known Mount Samat (533 m.) in Diwa, Pilar also composes Mariveles Mountain.

The so-called Bataan Great Divide travels from north to south of Bataan along the upper edges of Mount Natib complex and Mariveles Mountain. A divide is a dividing ridge, as a mountain range, separating one drainage area from others. It is also called watershed, the area that drains into a river or lake.

All rivers on the west side of the dividing ridge travel downstream toward the west into the South China Sea, while all rivers on the east side of the dividing ridge travel downstream toward the east into Manila Bay.

Ridge is the line made where two sloping surfaces come together.