I felt I had to write a review as the reviews on here are so mixed! The Grotta was great as long as you go with realistic expectations. Don't catch the boat from Amalfi - it's probably not worth that much investment. It's a cheap and cheerful trip that's very easy to get to from the road (there's even an elevator, and a very good ceramics shop with a cafe and toilet close on hand). It's simple, charming and good fun - as long as you don't take yourself too seriously. If you want the Blue Grotto then get organised and go to Capri, but if you want a simple lark with the family then this is 10 euro you won't regret. It's also very near the Fiordo di Furore which is great - they make a good double. Our kids loved them both.

We were on a boat tour from Positano to Amalfi and back. We had an option to stop at the Emerald Grotto on the way. It sounded interesting so we decided to stop. What a waste of money (10 euros each). The cave is tiny. The "tour" involves you and about 19 other people getting into a small boat with a guide who rows around the cave to point out the few stalagmites and stalactites. There is light that comes in from a tunnel that makes a small portion of the cave look emerald. This only happens if there is direct sunlight. Not worth it so don't waste your time or money.

It was discovered in 1932 by a local fisherman in a cave perforated by a coastal cliff on the Amalfi coast, between Positano and Ravello. A narrow entrance to the cave is reached by an elevator down to the shoreline. Once inside, a not-so-large space spreads out and you get on the boat and admire it. There is a point at which the sun shines through a crack beneath the surface of the ocean, where the dark blue water shines more cobalt blue than emerald green. That's beautiful in itself, but I can't deny that it's a bit overkill, with the boatman singing songs and daring to make waves with his oars to diffuse the light. Since it is a modest tourist spot that is not as large as a tour, I guess they are trying to cover it with entertainment. The cave is covered with limestone stalagmites and stalactites, common in karst caves.