Newcastle has some beautiful beaches and coastal scenery. From Newcastle Beach there's a lovely walk which extends for several kilometres north and south, with plenty of great views along the way. I preferred the northern section though, and when I was there I was lucky enough to see some pelicans and dolphins.
From Newcastle Beach it's an easy stroll to Nobby's Beach. If you have time it's worth stopping along the way to take a tour of Fort Scratchley. Then continue walking on past the lighthouse to the end of the breakwater. This is a nice place to view the sun setting over the harbour.