The volcanic island of Santorini lies north of Crete. And this day trip by fast boat is a great chance to take a close-up look at it. Curved around a colossal, sea-filled caldera that was formed by a volcanic eruption 3,500 years ago, it’s all black cliffs, whitewashed villages and blue-domed churches, so it’s picture-postcard Greece. Once you’re off the boat, you’ll take off on scenic tour, ticking through many of the island’s highlights and learning about its history. Explore a caldera-edge town, where whitewashed houses, cobbled streets and tavernas descend down the cliff-face in steep terraces. Snap up treats at the island’s shops and boutiques. And visit some of the best viewpoints to take photos - the views over the caldera are great.