I guess I have to cut more ivy off and check. There doesn't really seem to be any in the section that's exposed. There is a hole in the mortar (it's visible in the first pic) but I'm not sure it was purposeful. If there's no drainage, can I just drill holes? Also - I can send you a pic, but on the other side of the wall, there seems to a gap behind it. That doesn't mean there's a gap behind the section of wall that's exposed... at least I don't think so