The Grotta of Smeraldo (tickets included) known as well with the name of "Emerald Cave" was named after the characteristic green light inside the cave. It is caused by natural sunlight from outside which enters the cave through an underground passage, which connects the salt water lake in the huge chamber with the sea outside. The water filters the sunlight and only green wave lengths reach the cave. You will enter the cave through an artificial tunnel. Inside there is a jetty with numerous wooden boats. The boat ride is the actual tour, so after a short look around you may enter the next boat and enjoy the calm gliding of the motorless boat. In rare cases, of very bad weather and sea conditions entrances to Emerald Grotto could be cancelled, from official management, in this case, outside our control, you will spend more time to visit the Amalfi Coast panoramic views. No refund is due.