Groups such as the International Civil Aviation Organization establish worldwide standards for safety and other vital concerns. Most international air traffic is regulated by bilateral agreements between countries, which designate specific carriers to operate on specific routes. The model of such an agreement was the Bermuda Agreement between the US and UK following World War II, which designated airports to be used for transatlantic flights and gave each government the authority to nominate carriers to operate routes.
Islets of Proizd and Ošjak: Visit the islets of Proizd (a famous beach in the area) and Ošjak – two of the most visited destinations in the area. Proizd is a small island that can be reached by a small excursion boat featuring three beautiful beaches with turquoise waters, several walking trails and a small restaurant and cafe. A day trip to this island is highly recommended. Ošjak is known as the Love island because of its beautiful nature, peaceful surrounding, and tranquillity. Enjoy swimming in unspoiled waters, walking through a dense pine forest and exploring an interesting cave.
Can you see all the major sights in Athens in one day? No. But you can see the Acropolis, Acropolis Museum, and the top historical sites of the Plaka in one day. If you had an extra half-day then visit the Archaeological Museum in Exarcheia. That still leaves many great sights but you will have seen all of the iconic Athens attractions. Adding Naxos is always a good idea. You might even enjoy it more than Mykonos (but no nightlife like Mykonos).
The Greek islands have beautiful weather in the months just before and after peak season. It’s a great time to see the islands, save money, avoid the crowds, and still have great weather (though not as hot as July and August). If you want to see the super-popular islands of Santorini, Rhodes, Corfu, and Crete without the tourists then this is a great time to visit.