The Greek Sporades Islands are located in the Aegean Sea to the east and south east of Thessaly's Pelion Peninsula . There are 11 islands in the archipelago but only four are inhabited: Skiathos, Skopelos, Alonnisos and Skyros . Skiathos has an international airport and boasts some of the best beaches in Greece making it one the most popular destination of all the Greek islands . Neighbouring Skopelos also attracts numerous summer visitors but Alonnisos and Skyros are both relatively unspoilt and appeal to people seeking tranquillity and age-old island traditions untainted by mass tourism. These Greek islands are characterized by dense vegetation and mountainous terrain and are world known as some of the bluest and cleanest seas one will ever come across and experience. Each of these has its own beauty and charm and has something unique to offer the visitor.