The castle of Penedono was one fortresses referred in the donation of D. Flâmula (or Chamôa Rodrigues) to the Monastery of Guimarães (on 11 June 960); it was mentioned part of the properties inherited from her mother, D. Leodegúndia Dias, the daughter of Count Diogo Fernandes and his wife D.

[1][2][3] At the time of testament, the document had recommended the sale of the structure, in order for its monies to be used to help pay the ransom of captives, support pilgrims and assist monasteries.

[1] In 1195, in order to improve the strategic position of the border territory, King D. Sancho I conceded the region's first Foral (charter) to Pena de Domus, the medieval designation for the burgh.

[2] Between 1471 and 1530, under the authority of D. Francisco Coutinho, Count of Marialva, and responsible for the public works in the Comarca of Beira, the castle was transformed into a residence.

[1][2] Between 1940 and 1941, the DGEMN (General Directorate of National Buildings and Monuments) was responsible for excavations and debris involved in the construction of the mixed masonry walls, with lime mortar and sand.

[1] Further work was begun in 1969, that included the installation of oak ceilings, passage to the tower, cleaning and removal of weeds along the battlements, walls, merlons, staircases, pavements and accesses, leveling of the floors and substitution of the locks.

[1] The castle is situated in an isolate, urban area, implanted on a 930 metres (3,050 ft) rocky, hilltop and granite range that is part of the Serra de Serigo.

[1] The landscape is accessible by a frontal square by large granite landings and staircase and urbanized portions of Penedono that extend to the south and west.

[1] The polygonal plan forms an irregular heptagon, with a 70 metres (230 ft) perimeter, encircled by an undecorated, low barbican that accompanies the same elevation of the rocky hilltop.

[1] Between the two towers to the southwest, is a walkway with guardrail over the cornice, supporting a large arch over which is a rounded doorway (accessible by a flight of curved staircase) surmounted by a framed tympanum.