By boat or walking down the several hundred steps this is a great place and away from the crowds. the water is clear and you can swim through the rocks although the depth does drop off suddenly on the other side.
Anywhere on Capri you should always take your swimsuit and towel as the water is always inviting.
Swim through the arch and explore the beach. If you have access to it you most likely are on a boat and spending a leisurely day in the sea. This is a worthwhile stop while exploring the shoreline of Capri.
The view from the water of the long series of very step steps made me glad I was on a boat. The "Virgin Mary" like rock formation was inspiring. From the water the statue looked like its namesake.
I'm not sure the view in the cave would be as good
Marina piccola is real natural beaty but you can not find a place swim in the sea. The beach is horrible, it narrow and everybody on each other. The sun beds and umbrellas are too expensive. Everbody sit and lie where they can find places.