It's unlike my other 1869 maps in that it's printed on linen. Also, it's huge and very detailed. See that red square on it? I put that there so you'd get a sense of the scale when I show you what's under it:
What's even more remarkable is that this isn't even the whole map. It's all that was for sale, but if you look down the left edge you can see a border; that border is also along the top, but not along the other two edges. That's because this is less than one quarter of the original map. According to the writing in the top-left corner, there were 25 panels in all; I have only these 4.
I'm thinking it may have seen some military use...