Portugal [ˈpɔɹtʃəgəl] (help·info), officially the Portuguese Republic (Portuguese: República Portuguesa), is a country on the Iberian Peninsula. Located in southwestern Europe, Portugal is the westernmost country of mainland Europe and is bordered by the Atlantic Ocean to the west and south and by Spain to the north and east. The Atlantic archipelagos of the Azores and Madeira are also part of Portugal. The land within the borders of today's Portuguese Republic has been continuously settled since prehistoric times. Some of the earliest civilizations include Lusitanians and Celtic societies. Incorporation into the Roman Republic dominions took place in the 2nd century BC. The region was ruled and colonized by Germanic peoples, such as the Suebi and the Visigoths, from the 5th to the 8th century. From this era, some vestiges of the Alans were also found. The Muslim Moors arrived in the early 8th century and conquered the Christian Germanic kingdoms, eventually occupying most of the Iberian Peninsula. In the early 1100s, during the Christian Reconquista, Portugal appeared as a kingdom independent of its neighbour, the Kingdom of León and Galicia. In a little over a century, in 1249, Portugal would establish almost its entire modern-day borders by conquering territory from the Moors. The climate can be classified as Mediterranean type csa in the south and csb in the north, according to the Köppen climate classification. Portugal is one of the warmest European countries, the annual temperature averages in mainland Portugal are 13 °C (55 °F) in the north and 18 °C (64 °F) in the south and it is over 20 °C (68°F) on the warmest spots, like south coast of Madeira island. The Madeira and Azores Atlantic archipelagos have a narrower temperature range. Extreme temperatures occur in the mountains of Northeastern parts of the country in winter (where they may fall to -15 °C) and Southeastern parts in summer. Sea coastal areas are milder. Absolute extremes registered so far have been -23 °C in the big mountain of Serra da Estrela and 48 °C in the Alentejo region. There are registered values of 50,5 for Riodades. It is very plausible that these values can be registered on the Guadiana, Douro and Tagus (Tejo) warmest valleys. Mainland Portugal is split by its main river, the Tagus. The northern landscape is mountainous in the interior areas, with plateaus indented by river valleys. The south, between the Tagus and the Algarve (the Alentejo), features mostly rolling plains and a climate somewhat warmer and drier than in the cooler and rainier north. The Algarve, separated from the Alentejo by mountains, has a climate much like southern coastal Spain.