This is a book about a young boy, Michele, who sees a boat with red sails coming in to his home town of Capri. The boat carries 3 strangers, one looking for adventure, one for beauty, and one for truth. There is a mysterious grotto in Capri that is feared by all the locals. The story is about how these 3 strangers find what they're looking for in this mysterious grotto.
After I read this book, I found out that there's actually a real place in Capri known as Grotto Azzurra, or the Blue Grotto. I find it interesting that the people who discovered it were somewhat like the characters in the story!
The grotto was discovered by a local fisherman, Angelo Ferraro, in 1826 along with a German scholar and a painter. In the book, there's a fisherman named Angelo who planned the expedition to the grotto for the 3 strangers - a French explorer, an English painter, and a Belgian philosopher.
After reading this book and seeing pictures and videos of the real grotto, I have an urge to go to Capri to see it myself!