The Palace of the Counts was a palatial building in the Gothic style, whose construction began in the first half of the 15th century by order of D. Afonso, 8th Count of Barcelos and 1st Duke of Bragança. Originally a gift from D. Nuno Álvares Pereira to her daughter, the Palace was never inhabited by her. This building precedes the famous Palace of the Dukes of Guimarães, also from the 15th century, built by D. Afonso for his second wife, D. Constança, after his return from Africa.

Since the 20th century, the Palace of the Counts has housed the Barcelos Archaeological Museum. This museum presents a collection of pieces found in Barcelos, some discovered by chance and others through archaeological excavations. Among the artefacts on display are several tombs and other relics that offer a fascinating glimpse into the history and heritage of the region. It has been classified as a National Monument since 1910.