Found my walled courtyard easily enough. It is nestled among still standing buildings in the otherwise leveled East End. Having landmarks to go by prevented me from wasting the whole day looking for it.
Which was a good thing. Beforehand I had decided to allow myself just the barest minimum of time there. As it was, I was enabled to stay longer. What I learned I shared with Elijah and he in turn was able to warn everyone before we scatter to the four winds.