This threshold belongs to the later, imperial reorganization of the original long space between ashlar walls 7078/7073 and 7108. Together with walls 7114 and 7115, this threshold formed the limit between Rooms 4 and 5. It seems to have been designed in conjunction with the drain that runs from south to north between Rooms 4 and 5 (7196/7201), which clearly passes beneath it, where a gap was left to accommodate its passage.
Concrete wall running E-W at S limit of Room 5; Concrete wall running N-S at W limit of Room 5; Concrete wall running E-W at SW corner of Room 4; Stone threshold between Rooms H4 and H5; Concrete wall running E-W at SE corner of Room 4; Stone threshold between Rooms H4 and H5; Long ashlar wall running N-S at eastern limit of rooms 4, 5, and 6; Four large square tufo blocks along E wall of Room 5; Line of small stones along W face of blocks 7198; Cut into SU 7150 E of wall 7117; Fill of cut 7155; Cut into SU 7150 in center of Room 5; Fill of cut 7151
Model of Rooms H4 and H5
View from west
View from north