Investigations undertaken by the Archaeological Superintendency of South Etruria prior to the creation of the new line of the S.S. 2 Cassia road at Vetralla in the locality of “Mazzacotto”, revealed a stretch of the ancient via Cassia. This ran between the stations of Vicus Matrini, at the edge of the territory of Capranica (VT) and that of Forum Cassii near the hamlet of Tre Croci at Vetralla (VT), both mentioned on the Tabula Peutingeriana.

Here, the road was preserved for about 29 m and was only about 2.50 m wide. It was perfectly straight and showed signs of repeated restoration at various times during its very long period of use. It was used uninterruptedly and eventually became part of the famous Via Francigena or Romea used by pilgrims who from Canterbury or the heart of Europe, made their way to Rome to visit St. Peter’s tomb.

Stone blocks were documented, showing signs of wear from cartwheels, arranged in an irregular fashion that did not follow the direction of the road. This attests that during repairs blocks from the earlier surface were reused beside new blocks in “occhio di pesce” (leucite lava), a material which must have been more readily available in the period in which the restoration took place.

The scant nature of the road, also preserved in stretches found in the localities of and Pian di San Martino (Vetralla), seems to suggest that here, from the point of view of the ancient landscape, it ran through a wooded area. The deforestation prior to the building of the road must have presented a considerable undertaking for the craftsmen involved in the construction of a work whose technical characteristics were pared down to the minimum. Therefore, this section of road provides evidence for the existence of the dark and inextricable silva Cimina, mentioned by the ancient sources (cf. Liv. XI, 36: “Silva erat cimina magis tum invia atque orrenda quam nuper fuere germanici saltus”).