I want to do a week of walking in early May, somewhere in the dark blue zone you see on the map. I've done this kind of thing before - but always with hotels and hostels. This time I want to just sleep wherever I end up, with nothing but a hammock and/or sleeping bag. I have no problem sleeping under a bus shelter or something should the weather turn.

So I have two questions:
1. Where should I walk to and from? I assume I can cover 30km in a day, I do 20km most work days. I want to walk somewhere interesting, and obviously not too cold during the night.
2. Any tips for sleeping rough, especially at this time of year? I've never tried a hammock before but have heard it's good. Tent isn't possible because it's illegal in most places and too heavy.