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Field Trips

Bethells Beach | Mercer Bay | Nikau Cave | Otuataua Stonefields | Rangitoto Island | Waipu Caves | Whatipu

Do not linger at the entrances to sea caves.
The cliff rock is crumbly and rocks can drop without warning, especially when it's raining.
Rocks can also fall inside the caves, so helmets are recommended.

New Zealand has the 9 longest known sea caves in the world, and many other shorter ones.
Some of these, including several particularly impressive sea caves, are on Auckland's west coast.

  • Don't forget to check the batteries in your torches and cellphones are charged before going.
  • Take something to eat and drink, and appropriate clothing in case the weather turns bad.
  • Tell someone where you're going and when you expect to be back. You might well take longer, and some of the locations listed below are remote and isolated.

Bethells Beach (Te Henga) and O'Neill Bay sea caves

On the north side of the stream while walking out to the beach are a couple of caves – the larger of them is pictured at right.

At the south end of Bethells Beach is a large, open cave which was used for filming in Xena, Warrior Princess. South Bethells Cave can easily be accessed at low tide. At high tide some deep wading might be required, depending on what the sand level is like. A couple of small caves are nearby.

At the north end of Bethells Beach a more interesting cave can be found in Kotau Point, with several hundred metres of passages (and gold, according to one young boy walking his dog). The smaller of the beach entrances is called Sickman's Entrance because of the sound the sea makes when a wave splashes out of the hole at high tide.

The next bay north of Bethells Beach is O'Neill Bay, and features a nice (albeit small) through-cave at its northern end. It's about 1.8 km from the Bethells Beach carpark.

From the right spot at the north end of O'Neill Bay there is a view south straight through a cave in Erangi Point, the headland immediately north of Kotau Point – pictured at left (photo by M Paynter). The passage through the headland is 180 metres long, a distance which is just over twice the height of the 88 metre high headland, and is only a portion of the total cave in Erangi Point.

Erangi Point Cave and Kotau Point Cave were first measured in 2013, with additions discovered through to March 2014. At that time they were the second and third longest known sea caves in the world.

Erangi Point Cave is presently the third longest known sea cave in the world, and is more than twice the length of Kotau Point Cave, which is the sixth longest known sea cave in the world. (The longest known sea cave is 50% longer again, in Otago, New Zealand, and was only surveyed in 2011. It was the inspiration for us measuring these caves.)

  • ½ to full day trip depending on how much you want to see and do.
  • Shallow stream crossing if heading north along the beach.
  • Visiting Kotau Point Cave requires a low tide, preferrable a spring low tide with low swell.
  • Exploration of Erangi Point Cave is not recommended for children and requires low swell. It is an adventurous trip and completely foolhardy in rough weather.

Auckland Council info page.
Erangi Point Cave from a kayak.

Mercer Bay sea caves

A very steep walk down to the beach (including ropes in two or three places) gives access to some of the most impressive sea caves in New Zealand. This is quite an adventurous trip with incredible views, some incredible drops, and occasionally sea lions.

The longest sea cave at Mercer Bay is presently the fifth longest known sea cave in the world. It overtook Kotau Point Cave in June 2014; a 75 year old explored a side passage, realised it hadn't been included in the cave survey previously, so measured it.

At a casual glance this cave appears to be three separate caves.

  • ¾ day trip.
  • Requires a low tide, preferrable a spring low tide.
  • Requires above average fitness.
  • Suitable for older children and adults with outdoors experience; non-adults must be closely supervised.
  • This trip is not appropriate for beginners.

Some photos here.

Nikau Cave

This is a tourist cave about an hour and a half south west of Auckland. A nearby waterfall makes a pleasant walk through native bush.

  • ¾ day trip.
  • Suitable for all ages.

Trip report, Monday 8 April 2013.

In 2016 NZ Post issued some glowworm stamps that really glow in the dark. The $1.40 stamp is Nikau Cave.

North Head Historic Reserve tunnels

Gun emplacements and connecting tunnels make for an interesting day out, even in wet weather. Don't forget a torch.

  • ½ day trip.
  • Suitable for all ages.

North Head Historic Reserve.
Activities in North Head Historic Reserve.
North Head historic walk.

Otuataua Stonefields Historic Reserve

From the council brochure: This 100 hectare area has been established to protect and preserve the archaeological remains of the communities which thrived on this land for hundreds of years. It is one of the last volcanic areas of Tamaki Makaurau (Auckland) where you can see the large scale stonework and earthwork remains that show how people once lived and worked.

For the more adventurous there are lava caves that can be explored, although they are small and uncomfortable. Some of the grilles can be seen in Google Map's satellite view.

  • ¼ to ½ day trip.
  • Suitable for all ages, there's even a footpath along much of the coast.
  • No toilets, no food allowed within the reserve.

Auckland Council info page.

Rangitoto Island (including lava caves)

A great day away from the city, Rangitoto offers several lava caves and magnificent views from the summit.

  • Full day trip.
  • Suitable for all ages.

Rangitoto Island on Wikipedia.

Ferry timetable.

Waipu Caves

The Waipu Caves are a popular destination for day trips and offer activities for all levels, including caving (with glowworms!), rock climbing and abseiling, bush walks, and exploration. It's about 2 hours north of Auckland (longer in heavy traffic).

  • Full long day trip.
  • Suitable for all ages.

Sadly, in 2017 the idiots at the Whangarei District Council had an ill-conceived new carpark installed at the Waipu Caves Reserve, without consultation with any of the locals who know the place the best and use the place the most. The best shaded picnic spots have been destroyed and the place is now typically full of freedom campers – there for a free place to spend a night, not to enjoy the cave and its surroundings.

Photographic trip report, Sunday 12 October 2014.

In 2016 NZ Post issued some glowworm stamps that really glow in the dark. The $2.50 stamp is Waipu Caves – click for larger version. NZ Post's blurb for this stamp:

The Waipü Caves are in a scenic reserve about 10 kilometres inland from the little boutique village of Waipü. They were first used as tourist caves in the 1870s, a decade before Waitomo Caves, when tourists were transported by horse and buggy.

Tourists were actually visiting Waipu Caves in the mid 1860s.

Whatipu Scientific Reserve (including sea caves)

There are several caves in the cliffs north of the car park. The largest cave used to be used as a dance hall many years ago and there is possibly still part of the dance floor under several metres of sand. A "ghost" has been seen in one of the caves and what looks like a dinosaur poo in another.

  • ¾ to full day trip depending on how much exploring of the caves is wanted. (There are also camp sites.)
  • Suitable for all ages.
  • Accessible at any tide – the sea is over a kilometre away now.

Auckland Council info page.

In August 2013 year 9 student Roy H measured and remapped three of the caves as part of his science fair project. (The first map was made in 1970.) He ascertained three of the caves were the 35th, 39th and 74th longest known sea caves in the world at that time, and found some exciting lines of further research. His project won first place in its category and picked up another couple of awards as well. His maps were included in the June 2014 issue of the North Island Cave Atlas.