Cockatoo Island is located in Sydney Harbour and used to house a prison as well as being an industrial site used as a shipyard. Many of the structures on the island were built by convicts, and it is now heritage listed. It's a really great place to explore and take a picnic lunch. There's a ton of interesting dilapidated buildings, and often there are art shows and festivals on. If you're feeling even more adventurous, you can camp overnight! I haven't done this yet, but I think it would be fun to give it a go one time.
I was hanging out, minding my own business when a seagull challenged me to a staring contest. It looks like it won, but maybe my eyeballs followed it behind my sunglasses? How can you know?