Salento

Gallipoli "Città Bella" is a baroque town in the center of Salento that must be included in every visit to Apulia. In 1600 Gallipoli became the world capital for Olio Lampante. This oil was used to fire up the lamps in the world. There are 10 churches in this small town, one for each of the "Confraternite" who developed and became rich by delivering the Lamp Oil from its harbour.
Lamp oil was produced in underground mills "Frantoio ipogeo" where workers were used to live day and night with their donkeys used to move the big milling stones "macine or mollazze".

You can have a virtual tour here:

http://www.italiavirtualtour.it/dettaglio.php?id=94100

Giovanni Presta, from Gallipoli, developed in 1793 after 10 years of hard work interviewing farmers in Italy, Spain and Greece , the first essay on Olive Oil :

Degli Ulivi, Delle Ulive e del modo di cavar l’ Olio

(Olive trees, Olives and how to extract Oil)

After intensive search I found the book and I strongly recommend it to all who have a passion olive oil. I can help to get a copy.

Here is a quick extract translated in English :

Olive trees are the best trees by far :

Leaves never fall from the branches
Olive trees never die. You can cut them as you want after a while you see green leaves developing
Flowers are mono-petal and hermaphrodite
You can use its wood for heating fire. The fire is long lasting , fragrant, joyous and very warm ( 1000 additional Kcal/kg vs other woods)
You can extract from its branches a liquid (ragia) that will dilver a magic parfumes when burned into the house
You can easily conserve its fruits for all year
Olive fruits are gorgeous. You can eat them cold, fried, cooked, salty or sweet
If you press olives you get oil : the most perfect, delicate and sophisticated food and medicine
There is no waste from olive trees. Even the byproducts of olives milling can make money : nocciolino per heating, vegetal water for feeding the soil.