Sant'Antioco di Bisarcio

A Catholic diocese with seat in Bisarcium, in what was then the giudicato of Torres (one of the four independent quasi-kingdoms in which Sardinia was divided) or Guisarchium is documented from 1065 to 1503, when it was annexed to that of Alghero.

A first cathedral was built here in the late 11th century, but was later damaged by a fire, so that a document from 1139 suggests that the bishop had moved his seat to Ardara.

The portico, inspired by French models, has a lower storey with three rounded arcades, two of which included mullioned window (the left one closed).

On the narthex' right side is a staircase leading to the upper floor with three rooms, the central of which, provided with an altar, was the private chapel of the bishops of Bisarcio.

Behind the altar is a mullioned window opening towards the interior of the cathedral, sided by two decorative lozenges which can be seen also on the exterior walls of the apse, and are typical of the Pisane Romanesque style.