If you're interested in natural history, a visit to the Natural History Museum of Crete is a great way to spend a rainy afternoon in Heraklion. The museum showcases the rich biodiversity of Crete, including exhibits on the island's flora, fauna, and geology. You can learn about the unique ecosystems of Crete, as well as the various species that inhabit the island. The museum also has interactive displays and educational programs, making it a fun and informative experience for visitors of all ages.