Great Barrier Reef (Australia). 'UNESCO World Heritage–listed? Check. Oprah Winfrey–endorsed? Check. The Great Barrier Reef is jaw-droppingly beautiful. Stretching more than 2000km along the Queensland coastline, it’s a complex ecosystem populated with dazzling coral, languid sea turtles, gliding rays, timid reef sharks and tropical fish of every colour and size.' http://www.lonelyplanet.com/australia/travel-tips-and-articles/77668
Sydney Opera House. Designed by Danish architect Jørn Utzon and situated prominently on Bennelong Point in Sydney Harbour, it opened in 1973. The Sydney Opera House was designated a UNESCO World Heritage Site in 2007.