The Castle of Karystos is a historic fortress located on the island of Evia in Greece. Built in the 13th century by the Frankish rulers, it was strategically positioned to protect the town of Karystos and its harbor. The castle features impressive stone walls and towers, showcasing medieval military architecture. Over the centuries, the castle has undergone various renovations and changes in ownership, including periods under Venetian and Ottoman control. Today, it stands as a popular tourist attraction, offering visitors a glimpse into the region's rich history and stunning views of the surrounding landscape.