The Alps may be more famous, but the Pyrenees have been around much longer -- tens of millions of years longer. The Pyrenees formed 100-150 million years ago when the landmass that Spain occupies pushed into the one that France occupies. The mountains have served as a natural barrier between the Iberian Peninsula (Spain and Portugal) and the rest of Europe ever since. Stretching east to west across 267 square miles, or 430 square kilometers, the Pyrenees fall mostly within Spain’s borders, but also pass into the independent state of Andorra.
The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of part of the Central Pyrenees -- the highest part of the range -- on Aug. 1, 2000. In this false-color image, clouds appear white, snow appears pale blue, vegetation appears green, and bare ground appears as either pink or dark, bluish-purple. Water on the ground appears dark blue (or nearly black).
Image credit: NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team