The Oparara Basin is on the upper West Coast and at least a day trip from Nelson (~4:30h drive) or you stop by on your way in or out of Nelson.
The basin is a 35 million year old limestone complex which has been shaped by the deeply amber coloured Oparara River during the last million years cutting stunning caves, arches and channels. The area is covered with native old beech and podocarp forest and a blanket of moss and ferns. The whole area has an ancient feel to it where the only signs of civilisation are the car park and the well maintained tracks.
Birds, instects and bats are flourishing here and you hear birds chirping everywhere. Even 2 endangered species, the Whio (Blue Duck) and the Spotted Kiwi, call this area home.
The Oparara Basin is a beautiful short walks and day walk. All of them are graded easiest or easy by the DOC.
Just 200m from the car park you can see your first little cave with naturally formed 'paving' that looks like curled up squares. The cave is the natural habitat for cave spiders and Wetas and if you want to find them you should bring a torch or headlight.
When you leave the Crazy Paving cave you get to the Box Canyon cave which is much bigger and you'll need your torch to explore the depth of it.
The 4km long loop track takes about 1.30h to walk. It leads you though dense rain forest with Rimu and Kahikatea trees.
Along the track you'll come along the Moria Gate arch which was named, you guessed it, after the Lord of the Rings fantasy novel. However, that was in 1984 long before the movies became a New Zealand success story. Although smaller than the Oparara Arch it's still an impressive view with the tannin tinted Oparara River flowing through its middle.
Following the track you'll get to the Mirror Tarn which on a calm day reflects its surrounding bush beautifully.
The Ōpārara Arch is the biggest limestone arch in the Oparara Basin and the largest naturally rock arch in Australasia. It's a magnificent sight standing in the 200m long, 49m wide and 37m high rock arch.
The walk is about 2km long and take 50min return.
The 14km long track (one way) will take about 5h to walk. The Oparara Valley Track is a combination of Fenian Track and Moria Gate/Mirror Tarn Loop.