Peter Miller in Sydney has sent me a couple of pictures that show how things change.
Above is a picture of Fort Macquarie, built in 1817 to protect the harbour. This photograph was taken in late Victorian times, shortly before it was demolished to make space for a tramshed which was also built to resemble a castle, rather bizarrely.
Nowadays the site looks like this. I have no opinion on the architecture, but it is a pity that all the rowing boats have disappeared. Let's hope that more rowers follow Peter's splendid example and reclaim the harbour for real boats.