Oparara Basin Arches

The Oparara Basin Arches are a number of natural limestone tunnels formed by the Oparara River, in the Oparara Basin, New Zealand. The two most famous ones are the 'Oparara Arch', large enough for a multi-storey house, and the 'Moria Gate Arch', which is smaller in height.The arches can be reached by a forestry road from the main road approximately 9 km north of Karamea. The 12 km road is rough but can be accessed by normal cars most of the year. A carpark with a modern open shelter and toilet facilities just before the bridge over the Oparara River is the starting point for walks of around an hour return to each of the arches. There are also mountain bike tracks and a mountain lake in the area.Oparara ArchOparara Arch is the largest natural rock arch in the southern hemisphere. An old sign at the end of the walking track inside the arch lists the measurements as 200m long, 49m wide, and 37m high., however, the New Zealand Department of Conservation's measurements put it at 219m long, up to 79m wide, and 43m high.The southern entrance of Oparara Arch can be reached via a well-formed half an hour walking track which follows the Oparara River upstream. Shortly after the track crosses a bridge over a small tributary stream into Oparara River, it leads about one third of the way into the Oparara Arch, ascending up a series of wooden steps to end at a view point.The elevated view point is about two thirds up inside the height of the arch and takes in both entrances of the main arch as well as the Oparara River below. After rain, a small waterfall can be present in the center of the rock arch. The main tunnel is preceded (downstream) by an even taller, 10m long rock arch with a gap of about 10m to the main tunnel. Around the area of the view point, the start of the formation of stalactites and stalagmites can be seen.