About the antiquity of the Castle of Lamego, almost all the authors refer that the castle "is the work of the Moors" and prior to the foundation of nationality. From the primitive, only the keep (12th century), part of the old wall and the cistern (13th century) remain.

The donjon, about twenty meters high, is square in shape and has slits of light on its faces, some of which were altered in the 16th century to be turned into windows, by order of the last count of Marialva, D. Francisco Coutinho, perhaps in order to give the tower a housing function. It has a square of arms in the shape of an irregular hexagon, whose wall, with about ninety meters of perimeter, is equipped with an adarve, accessible from the north side by a flight of stairs.

Between 1939 and 1940, when the centenaries of the Foundation and Restoration of the nationality were celebrated, the castle underwent restoration work, with the bell and bells that existed at the top of the tower being removed to add the battlements. Access to the old castle town is through two open porches in the wall. Whoever enters on the north side passes through the arch called “Porta dos Figos or Fogos”, also already called “Porta da Vila or Aguião”, while the door on the opposite side is called “Porta do Sol”. Next to the latter we find an interesting emblazoned house that belonged to the Cistercian Order and later became the wheel house.