Time Out says
The largest of Warringah's four coastal lagoons, Narrabeen Lagoon facilitates a range of activities in company with the northern beaches. If a swim in the lagoon doesn't meet your standards of adventures, locals and visitors alike enjoy kayaking, sailing and paddle boarding or a move to the surrounding parkland for bushwalking or a picnic in the sun. The vast North Narrabeen Rockpool can be accessed by Narrabeen Park Parade at the entrance of the lagoon. A distinctive boardwalk separates the 70 metre by 40 metre pool from the 60 metre by 50 metre wading pool.