During the last few months I've made several trips to Manly, just a short ferry ride from central Sydney. Granted the main beach can get jammed backed, at night time the atmosphere can turn a little sour and the main street shouts 'g'day tourists,' I'm pretty fond of this little spot. If you ever get a chance to come here, this is what I suggest...
The ferry over is a great way to see the harbour, but if your bored of looking out at the shoreline and boats, make use of the free wi-fi on board.
Once the ferry is docked, walk to the small beach by the wharf. You might even be in the mood to buy something from the ice cream stand, However this is not the best beach Manly has to offer.
walk along the main street to manly main beach front, but still, this is not the best beach.
keep walking right along the 'cabbage tree park' area. Along this stretch of walk way you'll find water dragons, signs telling you not to take water dragons home, a salt water swimming pool, a cute little coffee shop and at low tide, flat rocks to sun bathe on.
Then you'll find one of my favourite little coves; Shelley beach. From here you can snorkel, swim and laze.
But if you're still wanting more, walk up the hill to a small amount of bushland set aside. There you'll get excellent views of the sea and during the right time of year, its whale spotting galore.