From St Arnaud to Punakaiki the rain hit; torrential downpours that meant slowing down. The blue Buller River, swollen with the rain, raged amidst the scree and rubble of the valley floor. We turned to follow the coast while the rain, swept in from the Tasman Sea, continued to hammer on the roof of our car. We pulled into Punakaiki just as the rain was easing. This small village offered us a cabin for the night set just back from the beach, as well as spectacular scenery. Giant banded sandstone and limestone cliffs towered over the beach, topped with thick forest spilling over the sides.

After the rain, white misty clouds clung surreally to the cliff tops while out of the mist, rolling lines of surf crashed relentlessly onto the grey driftwood-strewn sand. From the beach, the effect was one of timeless isolation.

The next day we wandered to the sea-carved rocks on the headland, and geyser-like blowholes. From there we strolled into the thick rainforest that stands between Punakaiki and the mountains to the east. Time dripped away like the rainwater off the palms as we lost ourselves in this scenery.

Another day on and we were on the move once more, heading southwards, further and further away from civilisation. Progress was slow, but this time it was the views not the weather impeding our progress. Every twenty minutes or so we were stopping for photos or just simply to stand and gawp. We finally ended up in Franz Josef, at the foot of a mountain range. In the distance, just below the cloudline, we could see the snow-capped peaks and below, tinged blue, the head of the Franz Josef Glacier.

This was why we had come to this remote place. But scenery isn't just there to be looked at. So, with the sun shining in a clear morning sky, we signed up for a glacier walk. The air is so clear here that distances are deceptive and it took us almost an hour to walk across the grey boulder-strewn valley up to the face of the glacier. Above us the ice tumbled its painstakingly slow way down from the peaks into the valley below. We climbed the lower slopes on steps cut into the dirty ice-and-gravel mix by our guides. As we crunched upwards onto the clear clean ice, we strapped crampons to our boots - bunches of steel teeth that allow you to grip the ice. After five minutes on the ice with them you feel like you can walk up walls. We tramped our way up into the whiteness above, our guide carving the steps as we went with a huge ice axe.

The scene before us was breathtaking. A rumpled blue-white ice sheet stretched out and up before us. The lower icefields were a brilliant white - composed of a dense sheet of packed ice crystals. The whole thing was pockmarked by the heat of the sun, making it look like a sheet of beaten metal. The ice itself is layered and streaked like a giant mint humbug, each line showing the shear and stress. The whole sheet is cracked by fissures where the ice has refused to bend anymore. Some are thin, almost hairline cracks, others giant corridors of dripping blue ice.

As we crunched and scraped our way upwards our guide pointed out depressions in the ice. Here and there the meltwater collects in small blue pools. Eventually these pools eat their way into the ice below, creating winding, gurgling sinkholes that drain away the runoff. These can become giant craters over time, filled with entire rivers of icy water that crash into the darkness hundreds of feet below.

Further up, the glacier led to the pinnacles - an icy landscape of peaks and valleys glistening and melting in the afternoon sun like frozen waves. Here and there the sun and meltwater bore through them creating twisting blue ice caverns. At the top of our journey - still some three kilometres from the jumble of tumbling ice at the head of the glacier - we paused and looked back. The ice sheet spread out before us, impossibly huge, cracked and buckled like some otherworldly landscape. The only sound is the trickling and distant flow of the meltwater funnelled beneath our feet. From down on the valley floor it had looked small, but standing up here you get a better sense of scale - it is a giant river of ice, slow, eternal and unstoppable, and you are but a small and fleeting thing.