There is a beach apart from the one near the Harihareshwar temple. Very few people seem to mention it. Its one of the best that i have seen On the way to Harihareshwar from Shrivardhan, dont take the road for the temple ( righter of the two) take the other road thats relatively straighther. It goes to the beach. You could also ask for M.T.D.C. Tents.. The stay there can be wonderful... At night you can hear the sea.. No other sound ! heavenly experience.
Do not visit on weekends / near new year. Only drinkers around :(