The Sporades are a group of four islands in the Aegean Sea. Skiathos, Skopelos and Alonissos lie close together. Skiathos has sandy beaches and a lively port town. Skopelos has a whitewashed main town and monasteries in the hills. Alonissos is quiet, and a national marine park around it protects the Mediterranean monk seal. Skyros lies farther south, with a castle above its main town and its own small breed of horse.