When the ice age ended it left behind many giant pieces of ice. These giant pieces of ice are known as glaciers. Most glaciers are found in Antarctica, Greenland, and North America.
When summer rolls in the glaciers partly melt swelling the nearby rivers, streams, and lakes. When a glacier in the Arctic melts part of it falls off the main piece forming an iceberg.
Usually, glaciers can be found in the mountains since it is cold there even in the summer and the glaciers there do not melt.