My all time favorite place on the Olympic Peninsula is Lake Crescent. Known for its brilliant blue waters and exceptional clarity which is caused by a lack of nitrogen in the water which inhibits the growth of algae. it is officially the second deepest lake in the state of Washington.
The lake was formed when glaciers carved out deep valleys during the last Ice Age. Approximately 8,000 years ago, a great landslide from one of the Olympic Mountains dammed Indian Creek and the deep valley filled with water.