It is the only nation with both a Red Sea coast and a Persian Gulf coast, and most of its terrain consists of arid desert, lowland and mountains. Saudi Arabia is the largest economy in the Middle East as of October 2018 and the 18th largest in the world.
The territory that now constitutes Saudi Arabia was the site of several ancient cultures and civilizations. The prehistory of Saudi Arabia shows some of the earliest traces of human activity in the world.
