Descriptive Attribute	Value(s)
Top (m)	Opening depth: 900.142 m at center.
Bottom (m)	Closing depth: 899.116 m at center.
Phase Description	Phase IV: Nabataean Grand Design: 1st c. BCE to CE 1st c. The remainder of the subterranean canalization is...
Stage	Stage 2
Definition	East-West Retaining Wall (equals Locus 4).
Stage Description	Construction of the West Staircase and Lower Temenos Retaining wall.
Phase	IV
Description	Locus 15 is a very well-built east-west Retaining/Terrace Wall, which is constructed through the southern part of the northwest and northeast quadrants of Trench 18. The lower courses are well-preserved sandstone blocks, some over two meters in length; their weight must be considerable. Above the squared-off blocks was a molding course like a reverse-cornice; this, however, is not well-preserved, and only one worn block is extant. Three weathered molding blocks found in excavation were restored to the east of the existing block. Above this course there must have been several meters of blocks extending upward to form the Temple Forecourt terrace of the Upper Temenos, but these have completely disappeared, being destroyed in the weathering of the ridge or stolen. To the west, the wall turns a corner or bonds with the East Wall of the Staircase; this is called Locus 4 and has been equated with Locus 15 (see below). Note also that this part of the Retaining Wall is most certainly the same East-West Retaining Wall of 1995 SP 4 which barricaded the Central Staircase.
Architectural or Soil Locus?	Architectural