Waianae Range

Waiʻanae Range (sometimes referred to as the Waianae Mountains) is the eroded remains of an ancient shield volcano that comprises the western half of the Hawaiian Island of Oahu. Its crest, at Mount Kaʻala, is the highest peak on Oʻahu. Like the neighboring Koʻolau, the Waiʻanae Range is not a mountain range in the sense most people are familiar with, as the mountain range as a whole was created from a single volcano.

Waianae Range in Days of Infamy
The Waianae Range served as a supposedly impenetrable mount-jungle terrain that kept the Imperial Japanese Army from overrunning the western part of Oahu. The only passage through the Waianae Range is the Kolekole Pass which was defended by a much less armed garrison. However, to the surprise of the Americans defending Oahu, the Japanese landed on Oahu's west coast and managed to climb over the mountain range and trapping the U.S. Army into a pincer.