The north and north-west of Sydney features beautiful beaches, lagoons and waterholes – some easily accessible, and others reached via bushwalking tracks. Unfortunately, the population growth of Sydney means some swimming spots can be too polluted to swim (I haven’t included these) and some are best avoided for a few days after rain.
See also wild swimming spots in Sydney’s south / Blue Mountains / Central Coast. The book Wild Swimming (by Sally Tertini and Steve Pollard) is also a great resource, with over 250 wild swimming spots around Sydney.
Curl Curl is a great surfing beach, but is also regarded as one of Sydney's most dangerous beaches due to its permanent rips. Both ends of the long beach have rockpools, a surf life saving club and kiosks.
A long surf beach on the northern beaches, which is popular with families. The northern end has a Suf Life Saving Cub and rockpool.
A deep and shaded swimming hole on Marramarra, The Duckpond is reached via a 5km (one-way) bushwalk, which an includes an off-track bushbash.
Collins Flat Beach is a sheltered harbour beach between between North Head and Little Manly Cove. It can only be reached via foot, via a couple of walking tracks.
The Basin Campground at West Head has beaches on both a Pittwater beach and a a lagoon, both of which are very sheltered. Access is via ferry or a firetrail from West Head Road.
A family-friendly beach with very calm water, Great Mackerel Beach can be reached by ferry (from Palm Beach) or via a couple of bushwalking tracks.
Hungry Beach is a picturesque West Head beach, which can be reached by boat or via a couple of informal walking routes.
A challenging beach to reach on foot, Flannel Flower Beach is a narrow sliver of sand, best visited at low tide.
One of the most picturesque West Head beaches, the sheltered Resolute Beach is reached by a walking track from either West Head Lookout or the Resolute Picnic Area.
The easiest beach to get to by foot at West Head, the sheltered West Head Beach faces Pittwater. and is opposite the Barrenjoey Peninsula. It's a nice spot for a swim.