The Chugoku region is the westernmost region of Honshu which is the largest island in Japan
. This region consists of the prefectures of Hiroshima, Yamaguchi, Shimane, Tottori, and Okayama. The Tamba region is considered a separate region from Chugoku and is made up of the mountains to the east of the Kako rivers as well as the Yura river valleys in the Hyogo prefecture and the Kyoto Fu of the kinki region.
This region consists of three land forms which are the Backbone Range, the Kibi Plateau, and the Iwami Plateau. The Backbone Range has a sharp divide between the Sea of Japan and the Island Sea. This is broken only by the gorge of the Gono River in the west. The Kammauri Mountains are said to be a separate region in itself. There are only a few mountain peaks in the region of Chugoku that exceed above 3,300 feet. The Kammauri Mountains though rises to 4,393 feet which makes it the highest mountain in this region.
The Backbone Range drops drastically in a steep trip to the Kibi Plateau to the south. The plateau is made up of eroded hilly land surfaces and has an elevation between 660 feet to 1900 feet. Intermountain basins are located between the Kibi Plateau and the Backbone Range. The main basins of this region are the Tsuyama, Niimi, and Miyoshi. The Iwami Plateau is considered narrower and more dissected than that of the Kibi Plateau. Many semicircular regions have been buried by lava here.