From the book: Jungle warfare will include all operations in a region characterized by a high annual rate of rainfall resulting in heavy growths of vegetation which hinder vision, movement, and fire. Jungle country may vary from the vast forests of Malaya, Burma and the highlands of Africa to the scrub-covered low hills of East Africa, India and the Middle East. The features common to these areas are: scarcity of roads and railways; limited visibility for both ground and air forces; and difficulties presented to cross country movement of all troops and vehicles. Much of the typical jungle country is broken by grassy open plains or sabanas where the vegetation is sparse and visibility good. These plains usually exist on ridges or upward toward the crest of mountains. The slopes of grassy sabanas are often steep and become very slippery when wet, making them difficult to ascend, particularly with heavy weapons.