Located on the east wall of the vestibule was a rectangular niche, sitting 1.30m above ground. Its walls, projecting floor, and aedicula façade were all constructed of grey marble. The façade consists of a wide slab used as pilasters on each side, with a similar slab used as an architrave at the top. Above sat a pediment formed by the narrow edges of slabs embedded in the wall. The floor of the niche features three holes which would have housed bases of statuettes. The interior was plastered.