Edge of abyss a ‘hole’ lot of fun

Be careful where you walk in Abel Tasman National Park. Brook Sabin visits the incredible 176-metre vertical sinkhole hidden in native bush.

The Abel Tasman National Park is best known for golden beaches, turquoise bays and bush-lined walkway. But its famous hike covers only a tiny fraction of the park, which is 22,530 hectares. The park extends inland for about 15km, and it is there you will find one of the region’s best hidden gems.

It was long thought Nelson Tasman was home to the centre of New Zealand; there is even a walk in Nelson called ‘‘The Centre of New Zealand Walk’’. The true answer is a little more complicated, and depends on where and what you measure, but I think it’s time to make things simple.

I have found the mythical centre of New Zealand, and in true Lord of the Rings style, it is suitably dramatic. Welcome to Harwoods Hole, the largest vertical shaft in New Zealand.

This giant hole is found deep in the Abel Tasman National Park on Ta¯ kaka Hill, about an hour-and-a-half drive from Nelson.

For such a remarkable feature, it spent most of its existence undisturbed.

It is believed that Henry Harwood, John Horton and Thomas Manson were the first to find the hole, and it was only officially explored by cavers in the 1950s.

The 176-metre vertical shaft was formed over tens of thousands of years, thanks to the limestone and marble rock that is widespread in the Golden Bay area.

Water reacts with the rock to produce a weak acid, which eventually erodes.

GNS Science has investigated the remarkable formation and explains, ‘‘Harwoods Hole itself formed from thousands of years of dissolution and erosion and, for a time, would have exhibited a spectacular waterfall from the lip of the sinkhole right to the floor.’’

However, that river was diverted to another sinkhole in the region, and it now lies dry.

The walk itself is a leisurely 45-minute stroll through dense beech forest, with a series of fascinating lime formations lining the track.

Near the end of the track the path forks, with two options to explore. The right trail leads to Gorge Creek Lookout, with spectacular views of the Ta¯ kaka Valley.

But don’t miss doubling back then heading to the hole itself. The lookout is about a third of the way down, giving you a sense you have been half-swallowed by the earth.

The Department of Conservation warns visitors that the hole is a ‘‘very dangerous place’’ and they shouldn’t continue up the rocks to the edge – you risk falling into the hole.

Scenes from Peter Jackson’s Lord of the Rings trilogy were filmed in this area, and it is not hard to see why. A visit will leave you with the impression that this is the one hole to rule them all.