They’re all great choices. Athens (1 to 2 full days) is great for historical sightseeing. Mykonos for beaches and nightlife (2 to 4 days). Crete for historical sightseeing, greek culture and towns, some beaches but spread out (4 to 7 days). Santorini has great sightseeing, tours, and some history (4 to 7 days). If visiting outside of June to September then drop Mykonos and do the other 3 for sure.
The delicate Great Barrier Reef is the earth’s most extensive coral-reef system, supporting more than 1,600 species of fish, along with whales, rays, octopuses, dolphins and more. Nestled in the heart of this world wonder are the 74 Whitsunday Islands, all but four of which are protected national parklands. Bask in luxury at a high-end resort like Hamilton Island, and book a seaplane or helicopter flight to admire sights like Heart Reef and the swirling silica sands of Whitehaven Beach’s Hill Inlet.
Other factors, such as surface transport facilities and onward connections, will also affect the relative appeal of different airports and some long distance flights may need to operate from the one with the longest runway. For example, LaGuardia Airport is the preferred airport for most of Manhattan due to its proximity, while long-distance routes must use John F. Kennedy International Airport's longer runways.
Patmos has an indefinable je ne sais quoi - an otherworldly quality that radiates from its crowning glory, the medieval monastery of St John. This turreted fortress, bursting with Byzantine relics, is named after John the Divine, who conjured up his apocalyptic revelations in a cave nearby. Pure-white Chora, a World Heritage Site, is where A-listers and fashion editors stay. High walls and heavy doors conceal magnificent mansions dating back to the 16th century.
The almighty church has kept nightlife in check. If you must see and be seen, head to quietly glamorous Astivi or Stoa bar, on miniature Agia Lesvias square, in Hora. Beach life is generally languid and low-key; Psili Ammos and Livadi Geranou are our favourite hideouts. Dinner reservations are essential at Benetos, for Med-Asian fusion on an organic farm, and Lambi for grilled fish on a purple pebble beach.