Near the end of the last glacial period, about 10,000 years ago, glaciers began to retreat. A retreating glacier often left behind large amounts of ice in hollows between drumlins or hills. As the ice age ended, these melted to create lakes. This can be seen in the Lake District in Northwestern England. Glacial lakes are often surrounded other evidence of the glacier including drumlins, moraines, eskers, striations and chatter marks.