The Portuguese territory forms a sort of strongly elongated rectangle in the NS direction (approx. 550 km), while in the WE direction the average extension is 150 km. The country corresponds geomorphologically to the western end of the ancient base of the Iberian Meseta, consisting of level granite rocks on which the sedimentary formations of the Mesozoic and Cenozoic overlap, in correspondence with the depressions invaded by the sea; in the Cenozoic era, however, there were strong orogenetic disturbances which are linked to the birth of the reliefs, both internal and coastal, of the entire peninsula, sometimes accompanied by volcanic events, which affected the southern mountainous extremity (Algarve) of Portugal. The Neozoic alluvial soils that occupy all the plains are also extensive, especially those of the major rivers: Sado, Mondego and Tago. The country is not morphologically uniform but with a succession of mountain ridges, hilly terraces and plains that descend from the edges of the Spanish interior plateau towards the Atlantic. with prevailing EW direction. A notable variety of forms characterizes the territory, in which the same mountainous fragmentation has given rise to regions that are distinct from a geographical and therefore socio-economic point of view; a first fundamental division is however operated by the Tagus, which separates northern Portugal, mountainous (regions of Minho, Tras-os-Montes, Beira Alta, etc.), from central and southern Portugal, essentially flat (Ribatejo, Alentejo, etc.). In the northern part the hoof has risen violently; it shows considerable fractures and the reliefs, an extension of the Galaico Massif and the Central Iberian Cordillera, are vigorous, culminating in the Serra da Estrela (1991 m), a long ridge that separates the Tagus basin from the Mondego basin. A deep incision in the reliefs of northern Portugal is represented by the Douro River, which flows in a heavily sunken valley. AS del Tago, on the other hand, lie the major plains of the country, in particular that of the Alentejo, where the western extension of the penepians of Extremadura Spanish slopes gently under a blanket of Cenozoic soil towards the low and sandy coasts of the Atlantic; this is the largest region of Portugal (about one third of the entire territory), closed on the southern side by the aforementioned mountains of the Algarve. The relief rarely reaches the sea, however never with very harsh shapes; the result is a rather regular coastal profile, characterized by extensive beaches, generally straight, with deep recesses only at the mouths of large rivers, sometimes swampy or closed by sandy strips.
From a climatic point of view, Portugal is subject to western Atlantic cyclonic influences, thus bringing humid air, and to subtropical anticyclonic ones. Although the territory is entirely open to the W to oceanic influences, these loosen towards the interior, where the characteristics of continentality typical of the Meseta are announced, and towards the S, where the country is now subject to the Mediterranean climate, characterized by very mild winters and from almost rainless summers. In summer, the entire territory is under the influence of the anticyclone from the Azores, coming from SW, which blocks the meteorological situation for many months: the sky is always clear, the temperature, on average around 20 ºC, rises sometimes reaching 40 ºC and the relative humidity is extremely reduced, up to 10% ; on the coast, however, the sea promotes a certain mitigating action. Towards autumn, according to findjobdescriptions, the arrival of Atlantic cyclones from the NW determines rainy conditions, especially in the northern mountainous regions, such as the Minho, where there is abundant rainfall (2500 mm per year against 500 mm in the Algarve). From a thermal point of view, there are quite significant differences between the northern regions, with long and rigid winters, and the southern ones, where the winters are warm and short (the average winter is around 3 ºC in Bragança, in the Tras-os-Montes, about 12 ºC in Lisbon).
To the eye of the observer the Portuguese landscape still appears rather wild: endless plains dotted with white villages, cork forests and marshes alternate with mountainous regions that are still sparsely populated. Even the vegetation of the country, covered by woods for approx. 40% of its surface is quite varied due to the climatic differences found in the various regions. The cool and humid climate of the northern areas is at the origin of the rich vegetation that turns the landscape green, with chestnuts, oaks and Scots pines; in inland areas, where rainfall is scarcer and temperature changes are stronger, meager pastures and scrub prevail. The wooded areas (holm oaks, cork oaks, etc.) are more limited to the S in relation to the hot and dry climate; widespread are vines, olive trees and maritime pines, in addition to the typical shrubs of the Mediterranean scrub (thyme, lavender, rosemary). Finally, there are numerous steppe areas almost devoid of vegetation, dotted with a few dwarf palms. In Portugal the fauna is characterized by the presence of numerous mammals, such as wolves, foxes, lynxes, wild cats, wild boars and deer. The country’s birdlife is also particularly varied, with numerous species of migratory birds. The spread of intensive cultivation has determined one of the most serious environmental problems in Portugal: the progressive impoverishment of the soil. Water pollution (quite serious especially in coastal areas), air pollution and waste disposal, problems that Portugal shares with many other industrialized nations, also threaten the health of the environment. Among the numerous protected areas, which occupy the 4, 3% of the national territory, the Penada-Gerês National Park, located in the northern region of the country, and the Serra de Estrela Natural Park are particularly noteworthy. In addition, the Madeira Laurisilva and the Alto Douro wine region, and the Pico Island wine growing landscape, have been recognized by UNESCO as a World Heritage Site.