Eskers are long and narrow mounds of gravel and sand formed by melting glaciers. It is believed that the stripes of eskers appeared 15-16 thousand years ago; they were formed by the water flowing through the glaciers. As the legends go, eskers are the trails of giants built over the swamps. Targiai Geomorphologic Reserve has been established to preserve the esker complex. The length of Targiai eskers ranges from 300 m to 2 km, the relative height is up to 18 m, and the width of the sole is up to 150 m. Only one third of it is visible on the surface, while the other part of the esker lies below the ground.