For military history buffs it's a must. But remember your cash and be self-sufficient on this island adventure, writes Paul Charman
If you own an adventure motorcycle, a fascinating day-trip awaits you that avoids tedious processions along SH1 or SH16 to escape Auckland. Why not take your bike on the ferry to Waiheke?
Round trip for bike and two passengers comes to $125, which seems pricey but provides an excellent hour-long voyage past inner gulf islands.
And, if time is short, you can easily cram this adventure into a single day, with a bike being perfect for island sight-seeing.
There's plenty to discover on Waiheke, between departing Wynyard Wharf (near the Tank Farm) at 8.30am and returning there from Kennedy Point at 4pm.
And while tastes vary, with some preferring cafes, restaurants and the sublime Onetangi Beach, others of us will zero in on Waiheke's remarkable military history.
This demands a 20km (45-minute) ride from Kennedy Point to the far eastern end of the island.
Colemans Suzuki loaned me their 2012 Suzuki V-Strom 650 ABS demo bike for this two-up adventure and the helpful Sealink staff shepherded us aboard their ferry, assuring us bikes don't require lashing down on the relatively short journey, as none ever look like falling off their side stands during the voyage.
They were right.
It was great gliding down the ramp aboard the well-balanced adventure bike, through the leafy residential streets, past Onetangi Beach and out on to the rugged metal roads leading to Stony Batter Fortress.
We seldom got out of third or fourth gear but, while a 250cc would have done the job fine, you just can't beat big cubes for two-up riding comfort.
The long-travel suspension soaked up all bumps and the tyres performed well in metal.
Our objective required an additional half-hour hike after parking, but it was worth it.
About 70 years ago, Stony Battery was New Zealand's top secret "Manhattan Project".
During the war, news that sister fortresses were being built at Whangaparaoa and Wrights Hill, Wellington, apparently filtered out as folk watched heavily-laden trucks rumbling past their doors and joined the dots as to where they were headed.
But supreme isolation, plus the fact that it was supplied from Man'O War Bay, meant nobody beyond military personnel and 180 or so workers had any inkling Stony Batter existed.
Yet this was the largest World War II fort built in New Zealand, the last 9.2 inch (23.4cm) gun fortress built anywhere in the world and our first major project to employ concrete pumps.
Stony Batter's radar-guided 9.2 inch guns could shoot well over the horizon (range 26km), to draw a bead on any Japanese warship entering the gulf.
But while New Zealand is prepared to celebrate a multitude of cultures, its own heritage is less respected.
Back in the 1960s, the unnamed idiots in power at the time saw to it that the guns, machinery and electric power were stripped out of the defunct fortress, then scrapped.
Heritage site or not, the Department of Conservation, which was made responsible for Stony Batter Fortress, then showed little inclination to open it to the public.
For safety reasons, DoC made plans to back-fill the entrance to the 1km-long tunnel complex.
The fact you can visit the fortress today, inspect some fascinating memorabilia and look through its tunnels by torchlight, is thanks to a few staunch Waiheke volunteers.
But remember, the place has considerable costs and runs on a shoestring. You need money to enter the underground complex ($5 child, $8 adult, $25 family - plus torch hire).
There are a few seats and some public toilets, but you need food and water bottles.
The billion-dollar views from the three gun emplacements are amazing and it was delightful to see rambunctious pet sheep guarding the tunnel entrance, and young children from around the island being trained as junior guides.
Members of the Stony Batter Preservation and Protection Society, led by Sue Pawley, make huge sacrifices to keep this place open.
My advice is go expecting to be positive, respectful and self-sufficient.
The V-Strom managed a full day-long trip round Waiheke, plus two joyrides from the CBD to Takapuna, all on about $10 of gas.