If you go to Thassos
https://maps.google.com/maps?saddr=4...1,0&sz=15&z=11
A: is a place where you should visit to go swimming. The beach is called paradise.
B: is a very nice village to go eating. Drive up on the mountain, feel the cold air and enjoy the view.
Of course, riding around the island is always a perfect expierience. I would suggest that you should do that and leave from Prinos (place C) to KAvala.
https://maps.google.com/maps?saddr=%...=h&mra=ps&z=11