The arch is rectangular, more akin to an
architrave than a typical
triumphal arch, and originally measured high. The opening between the interior reliefs measures wide. The lower register is constructed of unadorned
travertine, likely due to the frequency of cattle brushing against the sides. However, after the murders of Plautianus in 205, Plautilla in 211, and Geta in 212, their dedications were erased from the structure in an act of . The inside of the arch depicts two reliefs of members of the Severan dynasty. On the east side, Septimius Severus serves as the , while pouring a libation at an altar alongside his wife Julia Domna. Their son, Geta, was originally included in the relief, but his portrait was removed after Caracalla siezed power and ordered his murder. Likewise, the west relief depicts Caracalla makiing a similar offering at an altar, but his wife Plautilla and father-in law Plautianus were chiselled off. == Gallery ==