The smallest physiographic region of Honduras, the Pacific lowlands, is a strip of land averaging twenty-five kilometers wide on the north shore of the Golfo de Fonseca. The land is flat, becoming swampy near the shores of the gulf, and is composed mostly of alluvial soils washed down from the mountains. The gulf is shallow and the water rich in fish and mollusks. Mangroves along the shore make shrimp and shellfish particularly abundant by providing safe and abundant breeding areas amid their extensive networks of underwater roots.

Several islands in the gulf fall under Honduras's jurisdiction. The two largest, Zacate Grande and El Tigre, are eroded volcanoes, part of the chain of volcanoes that extends along the Pacific coast of Central America. Both islands have volcanic cones more than 700 meters in elevation that serve as markers for vessels entering Honduras's Pacific ports.

Data as of December 1993