The Mokihinui is a museum of landforms: in the east there is the Thousand Acre Plateau, a snow tussock-covered limestone slab perched above rim-rock cliffs and pocked with sink- holes; the western range, in contrast, is glacier-carved granite with sharp peaks, tarns cupped in cirque basins and deep, u-shaped valleys. Between the two ranges, rivers tumble through beech-forest-lined gorges, squeeze between limestone peaks and converge on an inter-montane basin. Here, the two main branches of the Mokihinui River spread out to braided meanders on an alluvial plain before plunging into the head of the 14-kilometre Mokihinui Gorge. The gorge descends through limestone, greywacke, schist and granite, through rapids and deep pools, before emerging to the coastal plain a short distance from the rollers of the Tasman Sea.