Sydney is the bustling, cosmopolitan heart of Australia, full of things to do and world-famous attractions to see. Book a Sydney Harbour sightseeing cruise from Pleasant Activities to check out famous landmarks like the Sydney Harbour Bridge and the Opera House, or take a walking tour of King's Cross while a local guide shares the scandalous hidden history of the area. For daredevils, consider the ultimate Sydney adventure activity - a climb to the top of the Sydney Harbour Bridge itself!