The olive groves changed color without warning — yellow edges, olives painted, the silvery-green of the leaves turning with the whims of a wind that is no longer the wind of August.

When Portugal's olive oil harvest happens, what goes on in the groves, and how to take part in Trás-os-Montes and Alto Douro. A practical guide for international visitors.

Some believe that in an olive grove in Vila Nova de Foz Côa, there are olive trees that were planted when King Afonso Henriques was still planning to conquer Lisbon.