The medieval keep of Chaves castle towers above the old town and houses the Museu Militar de Chaves, a military museum with a collection of weapons, armour, and documents tracing the town's long history as a frontier stronghold. The tower itself is the most striking thing: solid, square, and built from the dark local granite that gives the whole old town its austere character.
The views from the battlements reach across the Tâmega valley and north towards Spain. The surrounding garden area, once part of the castle defences, is now a pleasant space to sit. The museum is modest in scale but well-maintained, and for anyone interested in the history of this border region — contested between Portugal and Castile for centuries — it provides useful context.