The remarkable archaeological site was investigated from the end of the nineteenth century.
The fortified site was occupied probably from the bronze age, but the most extensive settlement was used from the second century BC to the first centuries AD. Later on, in the early middle ages, a little church was built in the acropolis. The investigations of the site, which has a considerable extension, are still going on. The first to explore the archaeological remains, Francisco Martins Sarmento, also built two circular buildings which were later on restored and can be still be seen today.