You may have heard of Portland, Oregon's Horse Project. My town still has lots of rings attached to its sidewalks, used a hundred-plus years ago for hitching horses and horse-led carriages when people needed to park. The Horse Project ties toy horses to the rings. All sorts of toy horses: I once saw a nearly foot-tall toy horse at SE 50th and Hawthorne.
People don't have to attach just toy horses, either. Seen today at SE 46th and Salmon: