The Sporades is a group of Greek islands in the northwest Aegean Sea. Four of them – Alonnisos, Skiathos, Skopelos, and Skyros – are inhabited. The islands are known for their beaches, wooded terrain, and coastal diving and snorkeling. Surrounded by uninhabited isles, Alonnisos is at the center of a marine park that’s home to dolphins and Mediterranean monk seals.