5009 spans the distance from 5010 and 5128 to 5008 and forms the northern limit of part of area F structure. 5009 appears to have gone trough several stages of use. It interlocks with 5128 at its western extent indicating that the two walls were probably constructed contemporaneously. There is a construction cut, 5074, along the northern face of 5009 probably associated with this first building phase. No construction cut was found on the southern face. It appears that later modifications were made to the wall, including corner 5106 which joins 5009 to 5008 and is constructed with large regular blocks rather than polygonal stones. There is also a rubble patch, 5105, visible only from the northern face and from above which may be the result of a later repair effort. The buttressing of the wall's southern face also seem to be later modifications. 5089, 5084, and 5088 are placed at approximately 3m intervals along the wall. 5009 sags visibly between 5084 and 5088 suggesting that the buttresses may have been part of a structural repair effort, though it is also possible that the sagging is the result of stress applied by colluvial sediments building up along the wall post-abandonment. The buttresses are joined to the wall by sections of mortared stone, further supporting a construction date for the buttresses later than that of the wall. It is unclear whether either face of 5009 looked out on to an interior space at any point.