About 9 km (5½ mi) northwest of Guimarães, this is the fascinating remains of a Celtic citânia (hill settlement). It dates from around 300 BC and was probably not abandoned until AD 300, making it one of the last Celtic strongholds against the Romans in Portugal, although its residents are now thought to have become gradually romanized. The walls and foundations of 150 huts and a meetinghouse have been excavated (two of the huts have been reconstructed to show their original size), and paths are clearly marked between them. Parts of a channeled water system also survive. The site was excavated in the late 19th century by Dr. Martins Sarmento, who gave his name to the museum in Guimarães, where most of the finds from Briteiros were transferred. If you intend to visit the site, don't miss that museum; you might also visit the smaller Museu da Cultura Castreja, housed in Sarmento's 19th-century family home, in the village of São Salvador de Briteiros, down below the Citânia. It contains finds from several local hill settlements and is open every day except Monday; entry is included in the Citânia ticket. There are several buses daily from downtown Guimaraes, but they stop about 1 km from the Citânia. It's easiest to get here by car.