Walls that separate Catholic and Protestant neighborhoods in Belfast are called Peace Lines.

Here are some multimedia features about them:

Still Divided is an audio slideshow from The Guardian.

Peace Walls of Belfast is another slideshow from The Guardian.

Here’s another slideshow.

Thanks to Ira Socol for writing about them. I had never heard of these walls before.

I’m adding these links to The Best Sites To Learn About Walls That Separate Us.