Sometimes big, sturdy walls provide nice little pockets to allow life to find protected spots. Once the wall is build, it doesn't take long for nature to reconquer the space which was taken by the wall.
Limit #15 Small Plants Make Use of Big Walls
I built this wall during summer 40 years ago, and today I returned to take a picture. It's amazing how not only my creation survived four decades, but how much plants and animals use this wall for their purpose. The whole thing looks nice by now, much nicer than the 7 feet high agglomeration of stones and mortar I put there when I had all of my life still in front of me.