Passage: The area includes about 185,180 square kilometers of deserts, plains, and mountains. It is divided into a coastal zone—with a narrow, double mountain belt enclosing a depression in the west—and a much larger eastern plateau. The climate is predominantly dry; about three-fifths of the country has less than 250 millimeters (9.84 in) of rain a year. Fertile land is the state's most important natural resource, and efforts have been made to increase the amount of arable land through irrigation projects.

Question: What is included in the 185,180 square kilometers?
deserts, plains, and mountains