One of a series of pictures with details of the arcade, that runs around most of the building, in the higher reaches of the several side. This is the north side, in the shadow at the time (rather dark, I am not quite satisfied with the result).

I was informed that an interlace pattern is part of medieval supersititons. The interlace was believed to trap the evil. Therefore, the interlace is a kind of weapon that protects the church from evil.