Spanish to English Social Sciences Architecture Church architecture

I'm working with an article about a church in Peru, with several references to both "portada de pies" and "muro de (los) pies." I believe that this must be the wall opposite the altar, where the main entrance or portal is located. I have found that the altar end is usually called the "east wall" but I just can't find a good term for that "other" wall. Is it the rear wall or back wall? But if you are standing outside the main entrance of the church, the rear would seem to be the altar end. So I think there must be a specific name for it, but I am coming up blank.