Take to the skies for a bird's eye view of Australia's crown jewel-the Great Barrier Reef. Stretching over 1,200 miles, the GBR is recognized as a UNESCO World Heritage Site. Between the outer edges of the reef and the mainland, there are more than 2,000 islands and almost 3,000 separate reefs. As the largest reef system on the planet, it's home to the world's biggest collection of coral reefs, with 400 types of coral, 1,500 species of fish and 4,000 types of mollusks. Impressive numbers, certainly, and a great way to appreciate its immense beauty is with a flightseeing tour that begins when you take off from Cairns Airport. On the return flight, you'll see Cairns, Green Island, Arlington Reef, Upolu Reef, Double Island and Palm Cove.