Geologically speaking, this zone consists of shale and greywacke, as well as some quartzite. However, the Zêzere river was also explored for iron and gold. On the banks of the Alge stream can be found one of the most significant relics of our country’s industrial history; the Foz de Alge ironworks, which lasted for three centuries of Portugal’s history. We are now under the influence of the waters of the Castelo de Bode reservoir, which changed the landscape in this region. Traditional three board boats can still be seen here, being used for fishing and transport across the river.