The first challenge with any trip to the Pearse Resurgence is getting there. The road is eroded and lined with large rocks – just the right size to ground a car.

The old benched track sidles high above the Pearse and above a deep gorge. After 45 minutes the track drops down to the river and basically continues crisscrossing the river.

Eventually, the valley broadens out to a grassy clearing large enough for a few tents. Whio (blue duck) can often be spotted in the river near here.

Above the campsite, the Pearse rises from an artesian spring. The water is so clear you can look through it and make out the various passages and caves leading down. Using mixed gases to offset the pressures experienced at depth, cave divers have descended some 220m into the cave.

The water from the Pearse comes from the karst massif above. Carbon dioxide rich water percolates into the karst, carving out marble shafts. Some are mere cracks while others are large voids, dropping hundreds of metres. Beyond is a labyrinth of caves with the longest system being 30km and 1000m deep. You could spend a lifetime exploring these.

The trip up the Pearse is a classic overnight trip, not far from Motueka and Nelson, the interesting karst features make it even more appealing and the campsite is a cracker.