This SU is a cappuccina drain composed of three visible tiles. It cuts through wall SU 6089. This drainage feature is much lower than another drain feature also in G-1 (SU 6119), and thus, SU 6216 appears to be part of an earlier phase of construction than drain SU 6119. Additionally, if our theory that surface 6161 extended across the extent of room G-1 and that the tufo surface extension SU 6217 is part of this earlier, now robbed-out, floor surface, then the cappuccina drain SU 6216 would be just below the early surface level of 6161 and 6217, dating it to one of the earliest phases of room G-1. Moreover, the tufo blocks SU 6177 may be related to the cappuccina drain in that they may be marking the sides of the currently obscured channel for the drain that we hypothesize would run under deposit SU 6178,