Another great option for a rainy afternoon in Heraklion is to explore the city's historical sites. Start by visiting the Koules Fortress, a Venetian fortress located at the entrance of the old harbor. From there, you can wander through the narrow streets of the old town, admiring the Venetian and Ottoman architecture. Don't miss the opportunity to visit the Loggia, a beautiful Venetian building that now serves as the Town Hall. Rainy weather can add a mystical atmosphere to these historical sites, making your visit even more memorable.