Aegean Islands
The Aegean islands within the Aegean Sea are significant tourist destinations. Tourism to the Aegean islands contributes a significant portion of tourism in Greece, especially since the second half of the 20th century. A total of five UNESCO World Heritage sites are located the Aegean Islands; these include the Monastery of Saint John the Theologian and the Cave of the Apocalypse on Patmos, the Pythagoreion and Heraion of Samos in Samos, the Nea Moni of Chios, the island of Delos, and the Medieval City of Rhodes.