Much of Portugal's territory is covered by mountains and highlands.

An excerpt from the article 37 facts about Portugal

Mainland Portugal (most Portuguese call the Iberian Peninsula a continent) is divided by the main river Tagus, which flows from Spain and joins the Atlantic Ocean in Lisbon. The northern part of the country is mountainous, then turns into plateaus crossed by river valleys, and in the south (Algarve and Alentejo regions) it is characterized by plains.