Yes, Santorini IS a Greek island. Or a series of islands. It is a volcano. http://www.santorini.net/caldera.html Its very beautiful there. It is very possible that Yanni was only 7 years old when he roughly wrote Santorini. He did start at an early age but he has perfected it over the years. Now it is one of his most moving and most beautiful compositions ever. I guess you could say it has evolved with the composer.
MAY YOU ALWAYS KNOW THE POWER OF LOVE AND THE BLESSING LOVING OTHERS BRINGS!