Everyone knows the Harbour Bridge and the Opera House area but some of the best views of both are to be had from two walks on the North side, namely Taronga Zoo to Balmoral Beach and Spit Bridge to Manly..Neither particularly arduous but good footwear and plenty of water a must!
Do also visit Garden Island and Cockatoo Island with their maritime connections , both only a stop or two by ferry from Circular Quay.