The Te Ana-Au Glowworm Caves

Why it matters

The naming runs the opposite way to the one everybody assumes. The lake and the town are named after the caves, not the caves after the lake. Te Ana-au means the cave with a current of swirling water, and for a long stretch of the nineteenth and twentieth centuries that reading was disputed — there was another that tied the name to a Waitaha chief's granddaughter, and no cave anyone could point at to settle it.

What settled it was 1948. Lawson Burrows spent three years searching the western shore, working from clues in Māori accounts of a cave there, and found the entrance. That is a rediscovery, not a discovery, and the distinction is the whole point: the accounts he was following were the reason he knew where to look, and the name had been carrying the answer for generations. (We have not found a primary Ngāi Tahu source for what was known before 1948, and we are not going to invent one.)

The geology is the surprise, and it is the opposite of what a limestone cave usually offers. These caves are only about twelve thousand years old and are still being cut. The Tunnel Burn — a stream fed from Lake Orbell, high in the Murchison Mountains — is still grinding its way through the rock, which makes this a live river cave rather than a finished one. The consequence is that there are essentially no stalactites and no stalagmites. Nothing has had time to grow. What you get instead is water: a waterfall you hear well before you see it, whirlpools, and rock scoured smooth and sharp-edged rather than draped. About two hundred metres of a system that runs to six and a half kilometres over four levels is open to visitors.

What it's like

The trip is built as a sequence of subtractions. First the town goes: a catamaran takes you across the lake, and the far shore has nothing on it but bush and a jetty. Then the daylight goes, on a short walk through beech forest to the cave mouth. Then the noise arrives, which is the reverse of what you expect underground — the first chamber is loud, a waterfall pouring through a slot in the rock with the sound coming off every hard surface at once, and you follow a walkway above the water with the whole cave roaring at you.

And then, at the far end, all of it stops. You get into a punt, the guide takes hold of a wire strung along the roof, the lights go out, and nobody is allowed to speak. The silence is a working part of the experience rather than good manners: glowworms dim when they are disturbed, so the rule protects the thing you came to see.

What is overhead once your eyes adjust does not photograph and does not really translate. It is not a scatter of points. It reads as depth — thousands of small green lights at slightly different distances, so the roof appears to recede much further than a cave roof should, and the effect is less like a ceiling than like being under a sky. Hanging beneath each light, if you could see it, is a curtain of fishing lines. The prettiest thing in Fiordland is a larva advertising for food.

How to visit

One operator runs it and there is no other way in: RealNZ, from the visitor centre at 85 Lakefront Drive in Te Anau. Four departures a day — 10.15am, 2pm, 4.30pm and 7pm — year-round, and check-in is thirty minutes before you sail. The whole trip is two and a quarter hours, of which about forty-five minutes is underground and the rest is the lake crossing and the walk.

It is from NZ$145 an adult. Children aged five to fifteen are NZ$69 and under-fives go free. You will see NZ$129 quoted on the national tourism site with no conditions attached; the live booking calendar does not offer it, so treat NZ$145 as the number to budget. Groups are small — a dozen or so, though the operator's own pages say twelve in one place and fourteen in another.

The cave is 8 to 12 degrees whatever the weather is doing outside, so a fleece is enough. What actually catches people out is the shape of the passage rather than the temperature.

Rain is not the problem you would expect — the cave is underground — but heavy rain is, because the Tunnel Burn rises fast and floods the walkways, and trips are cancelled when it does. A guide's account describes the stream going from a bubble to a roar and the water dropping again a couple of days later. Rough weather on the lake can also stop the crossing. The operator publishes no weather policy and no cancellation terms for this trip, so ask when you book rather than assuming.

Making the most of it

Take the seven o'clock sailing. All four departures see the same cave and the same glowworms, but the evening one returns you across the lake in the dark with the town lights ahead, and it does not have an afternoon of other plans pressing behind it. It is also the one that feels like an outing rather than an item.

The harder question is whether to do this at all if Waitomo is on your itinerary, and the honest answer is not the one an operator would give. The glowworms are the same animal doing the same thing in both places. Waitomo's grotto is larger, far more famous, reached by road, and costs about NZ$81 for a forty-five minute tour against NZ$145 for this. If your question is where do I see glowworms, Waitomo answers it more cheaply and you will not see a better ceiling here.

What Te Ana-au has that Waitomo cannot is everything around the glowworms. Waitomo is an old, decorated system in Waikato farmland, seen from walkways and a boat. This is a young cave with a river still cutting it, on a lakeshore with no road, reached by boat, in a national park — and the noise of the waterfall on the way in is arguably the better memory. Do both if you are passing both. If you must choose one on price, choose Waitomo. If you are choosing on the hour you will remember, choose this.

Either way, book it rather than turning up. Four sailings a day at a dozen people each is not many seats in a town that fills in summer, and it is the obvious thing to do on a wet evening — which in Fiordland is most of them.

Nearby

Everything here starts from Te Anau, and the caves are the town's best evening by a distance — which makes them the natural other half of a day spent on the road north or out on a fiord. They pair particularly well with Milford Sound, because a Milford day gets you back to town in the late afternoon with nothing planned and the seven o'clock sailing waiting.

The same lake carries a good deal more — the fiords on its western side, the bird sanctuary on the lakefront path, and the Kepler Track, which starts at the control gates a short walk from town. There are pages on the lake itself and the Kepler Track.