Lapis Gabinus slab originally used as part of a drainage channel along with Lapis Gabinus slabs 8404, 8399, 8407, 8358, 8357 and basalt slab 8400. This slab, however, is no longer currently in line with the drain channel and sits in between the drain channel stones 8399 and 8400. The stone was likely removed from the channel and used to fill in and put the drain out of use approximately the same time as SU 8353.
Room I-19.
photo taken from the north
tufo between 8399 and 8406