Rushcutter's Bay is a great park in Sydney's east with a couple of Cafe's and some beautiful scenery.
Walk through the park from New South Head road until you hit the water and then keep walking.
One end of the park you can walk down into the water (or let
your dog down into the water) and at the other end there's a great view across the harbour towards Taronga Zoo wharf.
If the sun's out the view over the water is amazing.
Part of the Park is a lead free dog park so there are plenty of cute puppies running around too.
If you do it in the morning be sure to stop at the cafe near the tennis courts for a breakfast roll (sausage, bacon & egg) and go eat it by the water to reward yourself for doing a thing.