Vaulted arched narrow cobblestone lane lined with stone houses. Medieval town of Mesta. Chios. Greece. The pentagon shape and fortifications of the town has its roots back to the 14th century when the city was ruled by the Genoese. Located on the southern side of the Greek island of Chios, Mesta is one of the Mastic villages known as the Mastichochoria which have dominated the cultivation of Mastic gum for hundreds of years. Chios Island is the 5th largest island of Greece and belongs to the North Aegean region island group.