Castelo da Aguiar da Beira was built in the beginning of the 14th century, in order to replace an old fortification that wasn’t able to guarantee the safety of the village.
Even though the castle is now in ruins, the trail between the Lago dos Monumentos Nacionais and the top of hill, where the ruins are located, offers a unique view of the region.
Source: Visit Viseu Dão Lafões