you can go to cinnamonbay.com

The bay is located on the North Shore of St. John between Maho Bay on the East and Trunk bBay on the West. It is a very beautiful beach protected by its location within the National Park. The only services are provided by the Cinnamon Bay campground (site referenced by myemi26again).

We had been to Cinnamon Bay for the day once when we were on a cruise and it was a beautiful beach! We just returned from a week on St. John and thought about going again since it was so lovely but so many people said that it tends to be one of the windier (and therefore, had choppier waters) than many of the other beaches in that area)... so we went to others instead. To be honest, all of the beaches we'd ever gone to on St. John were unbelievably beautifully pristine... each with their own characteristics.

Hello,

Cinnamon Bay is on St. John. It’s a nice beach; nice water, nice beach, good snorkeling. No beach bar. There is a little restaurant and convenience store there; along with the campgrounds. Restrooms/changing rooms. Lockers, water sports booth are there. There is a hiking trail and ruins across the street which is nice; get to hike, see ruins, go to the beach in one trip. It is safe. There are taxis readily available if you need one.

--Islander