The small church of Sant Blai stands behind Was Baronia, a noble 17th century building in the village of Les. Its smallness, including its semicircular absidal space, seems to indicate that the current chapel would have been part of the head of some other building in its period of maximum splendour or was perhaps the result of reconstruction work based on original elements.

The west wall, or head wall, which opens out of a semicircular arch, is wider than the actual body of the chapel. This points to the possibility that the building was prolonged with a wide nave which, at some unknown point, must have been destroyed by either the hand of man or by that of nature. Moreover, the presence of four windows for no apparent reason has also given rise to hypotheses associated with the possible former existence of a crypt.
Thus, this building, which would seem to be from the 12th century, has a very curious appearance which, to this day, poses question marks as to its original architectural and functional structure.