Portugal, officially Portuguese Republic, Portuguese República Portuguesa, country lying along the Atlantic coast of the Iberian Peninsula in southwestern Europe. Once continental Europe’s greatest power, Portugal shares commonalities geographic and cultural with the countries of both northern Europe and the Mediterranean. Its cold, rocky northern coast and mountainous interior are sparsely settled, scenic, and wild, while the country’s south, the Algarve, is warm and fertile. The rugged Estrela Mountains (Serra da Estrela, or “Star Mountain Range”), which lie between the Tagus and Mondego rivers, contain the highest point of mainland Portugal. In the 1st millennium bce the Celtic Lusitani entered the Iberian