In the morning after breakfast, we walked across the road to Waitomo Adventures, where we booked a caving trip to St Benedict's Cave. We were met by our guides, Riki and Dan, and it turned out we were the only two people on that trip that day.

We drove in a rickety white van to the cave, which was about 15 minutes away and on the land of farmer Haggas. As the owner of the land also owns whaever's underneath, they have to pay him 12% of our fees to be granted access.

When we got to their shed, we were kitted out with overalls, a helmet with a light on, a climbing belt and 'gum boots' (wellies, rubber boots). We walked to the entrance of the cave, where Dan gave us Caving 101, more specifically a short introduction to abseiling. He taught us how to clip ourselves onto the rope, hold the rope and slide down.

When we were ready for the real thing, Dan and Riki tested our equipment and I went down the first abseil, 20 metres deep. Riki took a photo when I was a few metres down, and then I had to wriggle through a tight hole before popping out in a big cave on the other end. Dan was waiting at the bottom. He told me I was on my own for the second, 30 metre one and I started going down, usually having my feet against the wall as you are supposed to, but occasionally slipping. It seemed to go on for ages before I hit the ground.

I unhooked myself and hooked myself onto the safety rope, and Keiron started coming down. When he got ther, Dan came down whistling. I suppose this was a walk in the park for him, with only two people to take care of. He told us that limestone is formed by shells and coral compressed together at the bottom of the seabed. Due to the earth's movement it moves to above sealevel and caves begin to form.

I walked over a huge pole with safety lines left and right, and was soon followed by Keiron and Dan. We climbed over fallen rocks, Dan told us the cave had collapsed a long time ago. The rocks were loose and there were occasional puddles of water, where the limestone was all soft and soggy. I was a bit worried about slipping but I managed to stay upright.

In the end we reached the St Benedict's cave. We had a chocolate bar and orange juice and Dan told us he had been working in the tourist industry for 8 years, but was now moving to the UK with his English wife to settle down. Somehow I found it quite difficult to picture him in a nine to five job. I had some trouble understanding him and got very confused when he called me 'mate'.

He showed us a shell fossil, the top half showed in the ceiling and the bottom half on the ground. The cave had collapsed a long toime ago and had split the fossil in two! After that, he took out a big torch and showed us the stalagtites (hanging down from the ceiling) and -mites (growing up from the ground) of the cave. They form by water dripping from the cave roof, leaving behind a deposit of limestone crystals. It takes 500 years for one inch to grow, and they are extremely fragile, even the touch of a hand leaves a greasy mark that can break down the stalagtite or -mite. If they get really big, the two can join up and form a pillar.

In order not to damage the cave, Dan had designed a flying fox, very similar to the playground version where you slide down on a cable, holding on with both hands. Of course we were tied to it, for safety. Dan jokingly said we could do it with our headlamps off, in the dark, but I wasn't sure if he was taking the mickey. In any case, you wanted your eyes open as the cave was extremely beautiful.

I went after he'd sent the first aid kit down and it was great. I raced down at speed and stopped with a jolt a few metres before the platform, so Riki, who was at the other end, could take a photo. Then I had to push myself forward until I was over the platform and Riki helped me down. Keiron joined me and Dan followed not long after.

The four of us walked through the cave, Riki shining a light on the prettiest or most impressive formations. It was amazing. She took another photo of Keiron and me and then we all crawled into the 'Hobbit hole', basically an airlock so the conditions in the cave remain the same. The outside did look remarkably like the door of a hobbit's house.

We walked uphill to the van (luckily only a short walk) and drove back to the office, where Keiron and I chose our photos and had prints made, they were pretty good! We got a loaf of bread and icecream and then had lunch.

In the afternoon, we went to the Glowworm cave. The cave was discovered in 1886 by Maori Tane Tinorau and Fred Mace and they have had tourists in them for over a hundred years... Nowadays, the caves are partly paved, fitted out with steps and lighting, you name it. It makes for a disneyfied experience, although it's still pretty amazing. The caves are visited by hordes of Japanese and loud Americans, all pretty pissed off they are not allowed to take photos, I imagine.

You first get to the Cathedral, where the acoustics are so good Dame Kiri te Kanawa (the famous Maori opera singer) praised them for their acoustics. After that, you get to see the fine threads the glowworm larva weaves to catch its prey. They are called fishing lines. The light the glowworm emits from its body attracks flies and moths, who think it's the way out of the cave. The glowworms that glow the brightest are the hungriest!

They are only adults for a few days, during which time they don't eat as they don't have a mouth, so they have to feed themselves enough in the larva stage to sustain themselves. We stepped into a boat and floated through the dark (if you make light the glowworms turn their lights off), seeing thousands of lights twinkling on the caves' ceiling.

In the late afternoon we drove back to the campsite and read our books in the sun.