Maria da Guarda Estate, located in Serpa, Alentejo, has an olive grove with about 1.3 million olive trees. It is one of the olive groves with the largest number of olive trees on an estate of Portuguese capital in Portugal, being a living legend that tells the art of making oil.

The history of the name of the farm is linked to a local person who had a vision of the Mother of God. In this vision, Mary remembers that, during the arduous agricultural work, each worker had their own Guardian Angel for work and so the yoke was soft, the load lighter and the work happier.

Archaeological records found at the Maria da Guarda Estate reveal elements such as the lagareta, a stone on which a Roman settlement was built, and where Lagaretta oil, a very exclusive brand, takes its name. It is a precious legacy and the prologue to the production of Alentejo and national oils. However, the vocation of the nearly 2 million kilos of oil produced annually in the oil press of the farm are dedicated almost entirely to exportation in bulk.