When I drove north to Northland, I took the direct route out of Aucks, Orewa - Warkworth - Wellsford (blue arrow).  For my return journey, I took the more scenic route, along the Kaipara Harbour. 
 
 

This harbour is the largest in the southern hemisphere.

But it's not used for much shipping activity, as the tides are a bit treacherous.
The harbour is known as a major sanctuary for northern hemisphere birds on winter-over.
 

 
One of the stops along the way was Cleasby Hill.
 
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Image set is south to west
 
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 and then west to north
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Another scenic lookout further south along SH 16.
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