One of the stops on our Cunard cruise was on the island of Santorini. It was magnificent. The island was broken apart when the volcano erupted taking most of the island with it and leaving a huge caldera that filled with water. The main island of Santorini is a half moon shape and the cities of Oia and Fira sit on top of the caldera edges 1000 meters above. You have to take a cable car, donkey, or walk up to Fira – some 600 steps. But the views are amazing!!