The church was constructed in the year 852 and has a rather distinctive layout. Essentially it is rectangular space with a barrel vault that then has smaller rectangular spaces appended to this on each of the four sides of the church.
In this regard it is technically a cruciform church, but a very unique form of one.
The two rectangular spaces found to either side of the nave do not seem to have much practical or liturgical purpose but are thought to have some co-relation to the Visigothic liturgical practices of the time in which the church was built.
The peculiarity of this church does not end there however. The presbytery is raised (and while this is uncommon it is not necessarily peculiar); what is, however, is that at the top of the steps that lead up to the presbytery we find a chancel screen. Most unusual though is that in the centre we find a low balustrade that, visually speaking, sits where one would expect to see an altar in a basilica in Rome -- excepting of course this is not the altar but rather a low wall and, what's more, despite being raised, there is no actual confessio here (which was frequently why we find churches with the presbytery raised). This curious placement is perhaps explained by the fact that this architectural element was in fact spolia that had been repurposed by the church's builders from an earlier Visigothic structure.
The altar itself sits at the highest point int he church within the Easternmost of the smaller rectangular spaces; a window sits directly behind the altar in a rather Byzantine like fashion.