Berowra Creek starts around Pennant Hills and flows northwards, until it joins forces with the Hawkesbury. It's not actually a creek in the strict sense of the word, but a drowned river valley estuary. 

Just south of the Audley Boatshed in the Royal National Park (a brilliant spot for kayaking, by the way), a tributary runs into the Hacking River. Known as Kangaroo Creek, it begins in the park. 

Stretching from Ku-ring-gai Chase National Park's southeastern corner and flowing into Pittwater near Church Point, McCarrs Creek has quite a few enviable spots to go for a swim. 

This is not just a river — it's a river with rapids. To get in on the action, start off along the Nepean River Walking Track. 

Glenbrook Creek's 17 kilometres begin in the Blue Mountains National Park — five-kilometres southwest of Linden — and end where the creek runs into the Nepean River.

The epic 74-kilometre Kowmung River runs through both the Blue Mountains and Kanangra-Boyd National Parks, passing some of the most rugged scenery in New South Wales. 

For a river that runs through residential areas, the Woronora is surprisingly clean. It's ideal not just for swimming but also for boating, canoeing, fishing and heaps of other water sports. 

Set at the start of the Royal National Park, the mighty Hacking River runs between Sydney's southernmost suburbs and Bundeena. One of the loveliest places to swim along it is off Swallow Rock Reserve, at the end of Swallow Rock Drive in Grays Point. 

Nayook Creek's most famous — and most swimmable — stretch is Deep Pass Canyon. Found at Newnes Plateau, it's home to several deep pools which are dotted with fairy-like ferns and cascades.