At the limits of the parish of Seixas do Douro we find prehistoric remains in the place called CASTELO VELHO, located next to the Teja stream, right there along the path that led to Numão. For the collected materials it will be a fortification of the final Bronze with a prolonged occupation during the Iron Age.

In the place of the Castle, very close to the so-called Alto das Seixas, but very close to the center of the current settlement, an Iron Age settlement, later Romanized, could be accommodated, as happened elsewhere (Mós, Freixo, Cedovim, Muxagata, among others).