How do glaciers shape valleys and lakes in the Pyrenees?

During and after the Ice Ages, glaciers played a transformative role in shaping the landscape of the Pyrenees.

Glacial activity significantly influenced the region's topography in the following ways:

• Valley Formation: The movement of glacier tongues served as the primary force in creating the deep valleys that contain the modern river system.1
• Lakes and Landscapes: The erosion left behind by glaciers created various features, including present-day lower lakes and idyllic meadows characterized by winding rivulets. These small mountain lakes, often found in steep-walled cirques, are known as tarns.12

While modern glaciers in the Pyrenees have been largely reduced to high-altitude basins and hanging valleys at elevations exceeding 9,800 feet, the widespread erosion and sediments deposited during the past 2.5 million years remain defining characteristics of the Central and Eastern Pyrenees.1