Horseneck Beach campground sites aren't particularly large, and are setup more for car camping and RVs than for tenting, but the site has great showers and a modern shower facility, and being able to walk out to the beach through the barrier dune to watch the sunset and sunrise is absolutely fantastic. I've camped here twice, once with a small group of 4 on one site, plenty big enough for all of us to have a tent, and once with a group of 15. Easy access to running water from most sites and pretty good, free, showers given the campground layout. Only downside is that the online reservation system requires a 2 night minimum, but calling the campground attendant can sometimes result in a one night reservation, especially early in the season when they're holding sites for last minute arrivals.

Hard to beat being less than an hour from Providence, RI and camping adjacent to a beach.