Oldest ancient sites in Portugal

Portugal's oldest site here is not a town but a tomb: the Great Dolmen of Zambujeiro near Évora, from the fourth millennium BC and one of the largest dolmens in Iberia. Conímbriga near Coimbra has an Iron Age first settlement, but its streets, houses and mosaics belong to the Roman town from the first century BC onwards. Citânia de Briteiros near Guimarães is a hillfort of round stone houses from the second century BC. The Roman ruins of Tróia, Cerro da Vila and Ammaia date from the first century AD.