Mesta is one of the 24 Mastic Villages in the south of Chios. Mastic gum is produced only in Chios and only in its south, due to the very delicate climatic conditions and the soil.
All of the villages carry something from the past, as they used to be under Genovese rule during the medieval times. Thus most of them look like they were protected through walls and fortifications.
Indeed, if you take a look at the map, you will notice that the villages of Mesta, Olympi and Pyrgi resemble fortified castles. That's because they actually were!
A short walk around the peaceful alleys of Mesta is something I recommend, as well as sitting at the main square for a coffee and some Chios-style "loukoumades" doughnuts!