One of the most popular beaches in Harwich, Red River Beach is long and quite spacious. Despite its popularity, there is still plenty of room to stretch out or play some Frisbee. The warm Nantucket Sound water is great for swimming. Some small waves make this beach great for kids who want to spend some time with their boogie-boards. You can also take your boat out for a ride here - travel to the very end of the parking lot to find the boat ramp.