The Asir Mountains (, ; ] ('Difficult')) is a mountainous region in southwestern Saudi Arabia running parallel to the Red Sea. It comprises areas in the 'Asir Region of Saudi Arabia, however it also generally includes areas near the Yemeni border. The mountains cover approximately and consists of mountains, plains, and valleys of the Arabian highlands. Sensu lato, they are part of the Sarawat Mountains, defining the latter as the mountain range which runs parallel to the Tihamah throughout the western portion of the Arabian Peninsula, particularly the western parts of Saudi Arabia and Yemen.