Harrat al Birk volcano (also known as Harrat Hayil or Hubhub al Sheikh) is the only young volcanic field of Western Arabia located directly at the Red Sea coast, west of the town of Abha, and between the Tihamat ash Sham and Tihamat 'Asir coastal plains. It consists of 1800 sq km of basaltic cinder cones and lava flows. Freshly eroded ash deposits are found around a vent at Jabal Ba'a, east of the main field, and suggest that an eruption might have occurred less than 100 years ago here.