Mourão was another of the border towns disputed by Spain and Portugal in the 13C until in 1297 King Dinis signed the Treaty of Alcañices with the Spanish King, Fernando IV, and Mourão became a Portuguese possession, although the fighting and disputes did not end. (The history of this town and its castle is very confusing, and this site shows there is no simple, quick explanation.)
The Castle was built during the reign of King Dinis’ son, Alfonso IV (1291-1357) by João Afonso. Further work was carried out in the 16C, and in the 17C fortifications were added in the Vauban style by Nicholas of Langres and Pierre de Sainte-Colombe who had also worked at Monsaraz. On the information board and Google Maps the Mediaeval walls are clear, surrounded by the 17C fortifications.
Inside the walls the buildings, apart from the Church, are in ruins. There are eleven square towers, and two, perhaps three, gates. We entered through the Church Gate with its two small guns, and there is another gate (blocked up) leading towards the Alqueva Reservoir.
There is a ruined building near the blocked gateway…
And more ruins alongside the Church, with a coat of arms I can’t identify…
The 17C fortifications (just visible under all the vegetation) can be found by walking around the outside of the Mediaeval walls.
A very easy walk to the 15C Chapel of St Sebastian, close to the Reservoir, leads away from the blocked gateway and down a flowery path.
And then it was time to turn round, return to the Castle, and drive back to Vila Viçosa.
You may be interested in
The History of Mourão
Portugal in a Campervan – delightful blog
Holidaying in the area
Mapping the Country – foreign engineers in Portugal in the 17C