[All] I'm curious what kind of wallpaper you all use!

What picture do you use as your default background? I change it often, but the one I've been using recently is a group photo! I've been changing it so often that I want to settle down, but I'm curious about what photos you all use as your backgrounds. Haha. By the way, my current background is the photo below. Haha. It's a famous photo, right?