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.