Tile drain likely in phase with SUs 6219, 6211, 6208, 6209, 6210 and used for a water feature in the northwestern quadrant of the room, and carrying the water out through a hole in the southern portion of wall 6187. Prep for mosaics, 6224, and mosaics 6221 and 6225 cover this feature and likely were the floor decoration for the room while the drain was in use.