Again, thanks all!
So, when you have some good sticks and a spare hour, these lumber piles are useful table scenics for blocking lines of sight and adding simple defences / barricades etc
I might be making a lumber mill at some point, so would also be good for that.
By the way, you can pick up twigs and sticks outside the house of course, but I found and used these inexpensive sticks at Pets at Home. Already clean and nice and straight.