Before the modern era, it was divided into four distinct regions: Red Sea Coast (Tihamah), Central Plateau (Al-Yamama), Indian Ocean Coast (Hadhramaut) and Persian Gulf Coast (Al-Bahrain). Hejaz and Najd make up most of Saudi Arabia. Southern Arabia consists of Yemen and some parts of Saudi Arabia (Najran, Jizan, Asir) and Oman (Dhofar). Eastern Arabia consists of the entire coastal strip of the Persian Gulf.