Is this a former volcano in the Hamad Plateau, in the Syrian desert?
My Rand-McNally Atlas shows the signature for lava fields in that area. The elevations in Google Maps indicate concentric contour lines with only small differences in elevation, rising from 600m at the outer perimeter to 700m in its center. This a shallow cone-shaped formation. Best I can tell from Wikipedia (compare the picture there), this feature is:


  As-Safa (Arabic: الصفا‎, Aṣ-Ṣafā), also known as Tulul al-Safa (تلول
  الصفا, Tulūl Eṣ-Ṣafā), Arabic for Al-Safa hills, is a hilly region
  which lies in southern Syria, north-east of Jabal Al-Arab volcanic
  plateau.  It consists of a basaltic lava field of volcanic origin,
  covering an area of 220 square kilometres, and contains at least 38
  cinder cones.


NASA Earth Observatory provides a satellite view as well and gives a few more details regarding the very noticeable dark area:


  Es Safa contains numerous vents that have been active during the
  Holocene Epoch (beginning approximately 12,000 years ago). The most
  recent recorded activity was a boiling lava lake observed in the area
  around 1850. The dark lava flow field (center) likely represents the
  latest activity of the volcanic field, and is emplaced over older,
  lighter colored flows.