When I think of fences keeping something in, I tend to think of emotional fences. We've never had a fence around any of the houses we've lived in, so I don't really relate to them physically.
All of our neighbors have had them though, to keep their pets in, except our current neighbor. I'm not really sure why he has one, but I think it's because he likes to garden. I can't see anything of his backyard except a tree with some very pretty pink flowers, a shed, and a few months ago he added some sunflowers that peeked over into our yard.
I took this one rainy day a few weeks back. It doesn't show all of the fence because my brother's roofing materials were in the way
My response to Mary's prompt is this:
No matter what
I won't take down the fence
Around my heart.
I've made that mistake
To read others' response to the prompt at The Imaginary Garden with Real Toads or to join in go here.