Museu Abade de Bacal is Braganca's strongest indoor sight and the best place to put the region's long, borderland history in order. The museum occupies the former episcopal palace and takes its name from Francisco Manuel Alves, the Abbot of Bacal, a priest-scholar who did much to preserve Tras-os-Montes history.
The collection ranges across archaeology, religious art, sculpture, painting, coins, textiles, and furniture. It is not a flashy museum, but it gives useful depth to a visit focused otherwise on the castle, Domus Municipalis, and the old streets inside the citadel. Allow an hour, more if you read Portuguese.