Walden Pond is a 102-foot deep pond located in Concord, Massachusetts, formed by retreating glaciers 10,000 - 12,000 years ago.

The writer, naturalist, and philosopher Henry David Thoreau lived on the shores of the pond for two years starting in the summer of 1845. His account of the experience was recorded in Walden, or, Life in the Woods, and made the spot famous.

Managed now by the state of Massachusetts, Walden Pond Reservation is a popular swimming destination in the summer. In the spring and fall, many people hike the trails that ring the pond and visit the site of Thoreau's one-room cabin.