New Zealand // The West Coast //

The Oparara Basin

Kahurangi’s finest limestone formations lie east of the Karamea–Kohaihai Highway in the Oparara Basin, a compact area of karst topography characterized by sinkholes, underground streams, caves and bridges created over millennia by the action of slightly acidic streams on the jointed rock. This is home to New Zealand’s largest native spider, the harmless, 15cm-diameter gradungular spider (found only in caves in the Karamea and Collingwood area, where it feeds off blowflies and cave crickets), and to a rare species of ancient and primitive carnivorous snail that grows up to 70mm across and dines on earthworms. Tannin-coloured rivers course gently over bleached-white boulders and, in faster-flowing sections, the rare whio (blue duck) swims for its supper. If your interest in geology is fleeting, the Oparara Basin still makes a superb place for day walks or a picnic.