Lucypower48
This small lake is wonderful for swimming and walking. There is a trail that takes you all around the lake. Folks enjoy fishing there. I've heard it is great for ice skating too though I've never tried it.
MassachusettsMishka
This is a refreshing (always cool water!) public swimming hole. Often crowded, and the beach isn't great for very small kids. But with no lifeguards one can really swim across the pond. There's a dog-friendly "beach" on one end.
Stormy013
My sister & I wanted to go to an out of the way place where there weren't a zillion children & had a great time here. It's basically tucked away & a gem.
amonly
Puffers is an easy way to get cool in summer without much prep. No motor boats, few homes. It is cool and has a community feel. Free too!