The Monadnock Region is home to several thousand acres of swimmable water, and while every boat launch can be used by anyone, there are three beaches that are open to the public (and not just local residents).
Spofford Lake, Ware’s Grove Beach: Chesterfield, NH
Open to anyone and accessible after a small fee, Ware’s Grove Beach is a wonderful way to spend a day on the lake with your family. The swimming area extends quite far and is very shallow for quite a ways, making it safe for your extra little ones to splash around (and there is a deep end for those more experienced swimmers). There’s a snack bar, kayak’s and paddle boards for rent, and most days a life guard on duty.
Otter Brook Lake: Keene, NH
Otter Brook Lake offers many recreational opportunities that everyone can enjoy. It offers a picnic area with 90 tables and 55 fireplace grills; swimming on a 400-foot-long beach; a boat ramp; boating for canoes, rowboats, sailboats, and motorboats (no wake); and sanitary facilities. During the winter, visitors enjoy cross-country skiing, ice fishing, snowshoeing, and snowmobiling.
Otter Lake: Greenfield, NH
Located in Greenfield State Park, there are multiple beaches that are open to the public (with a small fee). There are multiple beaches to choose from, and you can even rent a canoe or Kayak. There is the option to camp overnight here as well.