[citation needed] Evidence included it dating from the late 15th century when Jews settled near the Portuguese border due to increased persecution in Castile, and its architectural similarity to the Synagogue of Tomar in Portugal.

The roof disperses rain in four directions, forming a pyramidal structure The one entrance through the west side enters in to the main prayer room, where there are four granite columns with Doric bases and capitals.

[1] According to historians Carmen Balesteros and Jorge Oliveira, the two doors which are no longer used due to new buildings, used to lead to a side hall and the women's prayer room.

Another Portuguese coin from the mid-15th century in the foundation of the columns indicates that it was around that time that the building was first used as a synagogue; the deteriorating political conditions for Jews in the Crown of Castile meant that a position on the border with Portugal was preferred in case of needing to flee.

[1] The identification of the structure as a synagogue by Balesteros and Oliveira was controversial in the field of Jewish medieval archaeology in the 1990s and early 2000s, as it was based entirely on material evidence, as no documentation attests that the building was used as such.