The Mastichochoria, or mastic villages, occupy the southern part of Chios, the only region where the mastic lentisk has long produced its celebrated aromatic resin on a commercial scale. Islanders collected mastic in antiquity, and the product became valued for medicine, flavoring, perfume, varnish, and ritual use. The villages visible today, however, owe much of their form to the Middle Ages, when outside rulers sought to protect and regulate a crop whose rarity gave it exceptional economic and political importance.

Genoese forces took firm control of Chios in 1346 and governed the island until the Ottoman conquest of 1566. Under the commercial association known as the Maona of Chios and Phocaea, mastic production became increasingly systematic. Southern settlements were consolidated or reorganized into fortified villages that made workers and harvests easier to defend, supervise, and tax. Twenty or more communities formed this specialized landscape. Pyrgi, Mesta, Olympi, Kalamoti, and other villages combined agricultural production with architecture designed for insecurity and close communal life.

A typical mastic village had a compact plan, narrow twisting lanes, limited entrances, and houses joined into an almost continuous outer wall. A central tower or fortified core offered a last refuge, while flat roofs and bridges could connect neighboring buildings. This arrangement reduced exposed perimeter and confused raiders. In Pyrgi, later façades became famous for xysta, geometric black-and-white patterns scratched through layers of plaster. Mesta preserves an especially complete maze-like plan. Churches, cisterns, gates, storage spaces, and dwellings reveal communities built around both defense and production.

Cultivation shaped the year. Growers cleaned and prepared the soil beneath each lentisk, cut the bark during the dry season, and gathered the translucent drops after they hardened. Families then cleaned and sorted the resin through exacting hand labor, much of it traditionally performed in household and neighborhood groups. Genoese administrators treated mastic as a controlled monopoly and punished illicit trade. The system tied the architecture of the villages to Mediterranean markets reaching Italian ports, the Ottoman world, western Europe, and beyond.

Ottoman rule preserved special arrangements for the mastic district because the crop remained valuable to the imperial court and treasury. During the violence that devastated Chios in 1822, the mastic villages initially received a degree of protection, although insecurity, punishment, and later reprisals still affected their people. The destructive earthquake of 1881 damaged many southern settlements and killed large numbers across the island. Rebuilding changed some structures, yet the fortified plans, stone houses, decorative traditions, and agricultural terraces survived in varying degrees.

The Mastichochoria remain inhabited cultural landscapes rather than frozen medieval monuments. Cooperative organization and modern processing have altered the mastic economy, but cultivation still depends on local knowledge and seasonal practice. In 2014 UNESCO added the traditional know-how of cultivating mastic on Chios to the Representative List of the Intangible Cultural Heritage of Humanity. The villages therefore preserve two inseparable histories: a built environment created under Genoese and Ottoman systems of control, and a living agricultural tradition through which residents continue to shape southern Chios today.