The first is based on reality - a country called Occitania between France and Italy which existed as a cultural group until recently (and could be said to still exist) - see here for the wikipedia entry on the Occitan language (known as Provençal in England). Not very adventurous, but am working on it.
The second would be a small island in the Atlantic, effectively Atlantis, somewhere north of the Azores between Ireland and Newfoundland. This is the one I haven't thought too much about, so would be open to ideas.
The third is a bit controversial and probably won't fit in with the ground rules. I'd like a small city state to have existed in a large valley in the Welsh Black Mountains for the last 800 years or so as a last vestige of the original British people. I've got this last one worked out in quite a lot of detail, but will see what everyone thinks.