The Ancient Appia was the site were during one century (XVIII-XIX) two jesuits, Boscovich and Secchi, of the Collegio Romano did an important survey in order to study both the shape and dimensions of the Earth and the drawing of the Papal State cartography. In this comunication, authors would like to inform about the discovery of the manhole cover and of a piece of the stone cornice built around the geodetic baseline’s mark near an ancient monument in site Frattocchie. We believe to it is concerning the final mark of the geodetic baseline measured by Secchi in the middle of the XIX century with the witness of documents and comparing it with the one discovered in 1999 in front of the monument named Cecilia Metella.