What is the natural boundary that extends 20,000 square miles and separates Spain and Portugal from the rest of Europe?

Pyrenees Mountains. The natural boundary that extends 20,000 square miles and separates Spain and Portugal from the rest of Europe is the ___ (mountains). Map of Spain and Portugal, Corrected and Augmented from the Map Published by D. Tomas Lopez. 1810. Spain is a country located in southwestern Europe occupying most (about 85 percent) of the ... Most of Spain's boundaries are water: the Mediterranean Sea on the south to the French border and the Atlantic Ocean on ... The natural boundary in the southeast is, however, now considered by ... The continent extends west and east through nearly 75 degrees of ... In proportion to area it has a much longer coast-line than any other continent, over 20,000 miles, ... (3) The rest of Europe, from Bohemia to Spain and Scandinavia, ... The primitive boundaries of nations were mainly natural barriers, such as ... Spain, Portugal, France, and England took up the work of exploration and dis - ... The manufactures and commerce of Europe exceed those of all the rest of ... The area of Ireland is about 32,000 square miles, and its population nearly 4,500,000.