Most of the archaeological site of Rocha Forte was covered in stone from the walls of the towers and castle. Amidst this impressive debris, granite bond stones, artillery stone balls and some hand-chiselled pieces were strewn about. Each of these stones has its own history and function. For instance, the one shown in the illustration is a piece of a basin of holy water.
Evidence of its continued use can be seen in its inner face, worn away and polished by water. This small sculptural fragment, with the typical scallop-like decoration leads us to one of the mysteries of the fortress yet unsolved by archaeology: in the documentation of the Tavera vs Fonseca lawsuit there are references to the so-called «tower of Saint Euphemia», where there was «the church dedicated to the saint by that name». Witnesses provide differing versions as some indicate that the chapel was in the tower by the same name while others state it was beneath and others just locate it somewhere inside the castle.
The recent excavations have failed to shed light on the location of the religious building as no foundations or structures associated to the chapel were found at the level of the said tower. This circumstance leaves room for the hypotheses that the chapel was located in a room within the keep. In this context, the chapel was the symbolic core of the enclosure. Because of the agitated political situation of the time, the archbishop spent long periods at the castle where the nobility and the retinue of the prelate would attend liturgies.