The arch stands a few steps away from piazza del Mercato, the city’s old Roman forum, of which the arch was the triumphal entrance. The front features a still-visible inscription that informs that the arch was erected by will of the Spoletan senate in 23 AD, in honour of princes Drusus and Germanic, son and adoptive son of emperor Tiberius, respectively.
The arch is composed of big stone blocks and its decorations are scrappy. Starting from the Middle Ages, the arch was progressively absorbed by the neighbouring buildings, so much so that nowadays the western pillar is still non-visible, while the eastern one has been entirely brought back to light.

Museo Archeologico di Spoleto. La formazione della città dalle origini al Municipio (90 a.C.). Le sculture del Teatro Romano. Perugia, 2008; Museo Archeologico di Spoleto. Dal municipio all'età imperiale. Perugia, 2009; Morigi, Alessia Spoleto romana. Topografia e Urbanistica. Oxford, 2003