Java, with a population of 140 million, makes its first appearance on this list. Celebrated for its ancient culture, breathtaking vistas, and UNESCO World Heritage sites like the Borobudur Temple Compounds, the island also offers the opportunity to indulge in modernity (five-star hotels abound). Waterfalls, volcanoes, protected parks, and white-sand beaches also allow visitors to get away from the thrum.
Those are 3 great islands. Corfu is much more green than Crete and Santorini and does have a different feel (more Italian but it’s no where near Turkey). The trouble with doing all 3 is that Corfu is on the opposite side of Greece from Crete and Santorini so you’d need to fly via Athens. It’s better for most people to visit another Cycladic island (Naxos, Paros, Milos, Folegandros) instead of splitting up their trip between the two sides of the country.