Mangapohue Natural Bridge is a short, dramatic limestone arch you reach from a small gravel car park via a 10 to 20 minute track with steps and a timber boardwalk down to the river under the arch. Wear sturdy shoes and be ready for slippery, uneven surfaces after rain, and supervise children near the edges and steps. There are no facilities on site, it can get busy in summer so visit early for better photos, and you might see glowworms under the arch if you shine a light carefully. The walk is free and makes an easy add-on to other Waitomo area attractions.
For photography, take your wide angle lens with you for this one. There are some good photo opportunities from the board walk on the way in, and then from the bottom of the arch and then from up the stairs at the top. You will need your tripod with you as it is very dark inside in the archway.