The location of the Seo has its roots in the old Roman forum. Unlike other Roman city forums, the forum ofCaesaraugusta was not located at the confluence of the Cardus and the Decumanus, but instead near the Ebro river, adjoining the river port. The forum, besides being the civic and commercial center of the city, contained the main temple. The Museum of the Forum is found below the plaza del Pilar, across from the facade of the cathedral. There have been no remains found of either a Visigoth or a Mozarabic church.

http://en.wikipedia.org/wiki/File:La_Seo_de_noche.JPG

http://en.wikipedia.org/wiki/La_Seo_Cathedral