Time Out says
One of the most secluded beaches in the city is hiding in Ku-Ring-Gai Chase National Park
A trip to Resolute Beach should be a compulsory part of any trip to the stunning Ku-Ring-Gai Chase National Park. Looking out over Pittwater, with Barrenjoey Head and its picture-perfect lighthouse in the distance, it takes a little effort to reach Resolute, but boy, does the time invested pays dividends. You can reach these sands either by taking the Mackeral Trail from Mackeral Beach after cathing a boat across from Pittwater Park Wharf or by heading south on the Resolute Track from the West Head Lookout. Whichever you choose, your day at the beach will come bookended by a blissful bushwalk through some of the most beautifully unspoiled parklands near the city.