Walden Pond is a pond in Concord, Massachusetts, in the United States. A famous example of a kettle hole, it was formed by retreating glaciers 10,000–12,000 years ago. The pond is protected as part of Walden Pond State Reservation, a 335-acre (136 ha) state park and recreation site managed by the Massachusetts Department of Conservation and Recreation. The reservation was designated a National Historic Landmark in 1962 for its association with the writer Henry David Thoreau (1817–1862), whose two years living in a cabin on its shore provided the foundation for his famous 1854 work, Walden; or, Life in the Woods. The National Historic Preservation Act of 1966 ensured federal support for the preservation of the pond.
