On May 27, 1970, during construction of the Caffarella sewer system which was to serve new districts in the sprawling suburbs of Rome, the Municipality of Rome alerted the Soprintendenza to the discovery of some ancient structures near the via Appia.The area affected by the passage of the sewer system lies just beyond the Almo river, between the Appia's first and second mile, in a place where, at the end of the 19th c., P. Cartoni built a rather large barn for his estate (vigna). On the W side of the road, excavators discovered a concrete pedestal reveted with tuff blocks that was interpreted as the foundation of a sepulchral monument, the ruderatio of the via Appia, and a secondary paved road leading southeast, as published by L. Spera (see fig. 1, trench A). However, the excavations on the E side of the via Appia have never been published. The aim of this paper is to describe and interpret the remarkable discovery. My examination of documentation stored in the archives of the Soprintendenza identified photographs and sketches of the 1970 excavation, providing evidence for the existence of a Republican-era monumental architectural complex situated behind the barn of Vigna Cartoni. Since it was impossible unfortunately to locate any written reports, the research was based mostly on illustrations and administrative documents, but a fairly accurate history of the excavation could be reconstructed based on the latter.