The “Postierla” of the Conca is a minor gate of the Etruscan walls, not far away from the Arco Etrusco (Etruscan Arch), that, together with the one at the Cupa, was used as pedestrians gateway.
It can be dated, for its technical characteristics, at about the III-II Century B.C. It is right inside a medieval burrow, about 23 meters from the entrance. The external view of the gate is not really well visible, because of various subsequent works, while inside it can well be seen the arch, consisting of nine travertine wedges.
To the sides of the entrance, above, symmetrically, are embedded the ashlars with holes, where the hinges of the door were. The gate opens into a little rectangular passing made by square travertine blocks, placed using the same technique of the Etruscan Walls. It is covered by a barrel vault ceiling, in some places not in perfect conditions.
The gate, in time become unusable for pedestrian transit because of the a rising of the walk-over flooring, was restored and intercepted by a burrow, during the construction of the majestic medieval aqueduct in 1275-1277.
Coming all the way from the Monte Pacciano above the Arconi (Arches) of the present via dell’Acquedotto, the water reached the Fontana Maggiore in the close square.