In a few minutes it passes from an Alpine desert to the richness of the tropics.

At the bottom of the gorge is the river foaming among scarlet boulders--scarlet because of the lichen which coats them.

On either side rise slopes which are sometimes almost, sometimes altogether precipices, covered, every inch of them, with thick vegetation.

High above these tower the bare crags and peaks which, as the eye gazes upwards, seem to bend inwards, as though a single shock of earthquake would make them meet and entomb the gorge beneath.

In autumn the steeps are gay with crimson cushion-like masses of rata flowers, or the white blooms of the ribbon-wood and koromiko.
Again and again waterfalls break through their leafy coverts; one falls on the road itself and sprinkles passengers with its spray.