Fair Street crosses the Winnisquam River near the mouth and Winnesquam Avenue parallels the river to its mouth.

Lake Winnisquam in the Lakes Region of central New Hampshire is the fourth-largest lake entirely in New Hampshire, covering 4,214 acres and having a maximum depth of 155 feet. The lake is fed by the Winnipesaukee River, which also flows out of the lake to join the Merrimack River. Lake Winnisquam has two basins, a larger northern one and a smaller southern one, separated by a bridge carrying US-3 and NH-11. Lake Winnisquam offers a variety of recreational activities, such as bird watching, boating, swimming, fishing, hiking, golfing, and rail biking. The lake is surrounded by five towns: Meredith, Laconia, Sanbornton, Belmont, and Tilton.