More than 3,500 years ago, people on the Greek island of Calliste had a very good life. They enjoyed lots of sunshine, had plenty of food, and lived in large homes. They even had running water and flush toilets. There was only one problem: Calliste was actually a volcano. Around 1650 BCE, the volcano erupted, blowing out the center of the island and creating a large bay. What was left of Calliste was buried under a thick layer of volcanic ash. Though the island was deserted for many years, people eventually returned. Several centuries ago, it was renamed Santorini. The island has reclaimed its beauty and allure, but the volcano below continues to reshape this little plot of land in the Mediterranean Sea.