Glaciers and ice sheets are among the world’s most beautiful and fascinating natural wonders. Whereas today glacier ice covers approximately a tenth of Earth’s land surface, during the ice ages of the last few million years, as much as a third of the land surface was covered by glacier ice. Modern glaciers and ice sheets possess many interesting features that reflect their dynamics, their interaction with landscape, rock, sediment and water, and they also inform us about climate change. The legacy of ice masses is reflected in the presence of a variety of landforms and sediments, many of which are also recorded in the rock record. The value of glaciers to society is immense.