We will be traveling to Athens in June, and then working our way to Spain, but are unsure of the stops in between. Anyone with ideas on must see locations? We have approx. 2 weeks to travel & want to visit along the coast thru Italy.
Most of the well known Islands in the Cyclades would be out of the way for you, meaning that to go there you will backtrack through Athens. I would consider maybe focusing on the Peloponnese (Nafplio, Mycenae, Epidaurus, Sparta, Olympia) or maybe the Saronic Gulf Islands (Hydra, Poros, etc). Once you leave the Greece Mainland, on the way to Italy, you could also consider Corfu, in the Adriatic. In Italy, it would be pretty natural to consider Some route that would include Naples and Rome, or the North of Italy. Your biggest issue will be that you are covering a long distance in a short time, so to travel strictly by ground and ferry will mean a good 4 or 5 days taken up with just travel, leaving at the most, 5 or 6 stops in 4 countries, and brief stops at that. Maybe consider hitting a few limited stops (Athens, one place in the Peloponnese, maybe two stops in Italy) then fly to Spain. You can also fly from Athens to a number of places in Italy cheaply via Aegean Air, which may save you a day of travel.