What Are U Shaped Valleys? A U-shaped valley is a geomorphological formation that has steep, high sides and a flat or rounded valley bottom. These valleys are formed by glaciation. They are often filled with lakes rivers, sandtraps, sandtraps on golf courses kettle lakes (water hazards) or other natural features. https://www-sofasandcouches-com63715.digitollblog.com/29677942/this-is-the-good-and-bad-about-sectional-u-shape