- Region between the river Côa and the river Águeda, which marks the border between Portugal and modern Spain. This region has a series of medieval castles which were part of a defensive strategy against Castile. [CDJI, ii, ch.140]
- Castles of the Ribacôa defensive line: Alfaiates, Almeida, Castelo Bom, Castelo Melhor, Castelo Mendo, Castelo Rodrigo, Monforte, Pinhel, Sabugal and Vila Maior.
Notes: