One moment I beheld stupendous rocks hanging ruinous over my head; the next, I was enveloped in a drizzling cloud, which arose from a vast cascade that, dashing, thundered against the rocks below my feet.  On one side a perpetual torrent opened to my view a yawning abyss, which my eyes could hardly fathom with safety; sometimes I was lost in the obscurity of a hanging wood, and then was greatly astonished with the sudden opening of a flowery plain.

He was always charmed by ’a surprising mixture of wild and cultivated Nature’: 

Here Nature seems to have a singular pleasure in acting contradictory to herself, so different does she appear in the same place in different aspects.  Towards the east, the flowers of spring; to the south, the flowers of autumn; and northwards, the ice of winter.  Add to that the illusions of vision, the tops of the mountains variously illumined, the harmonious mixture of light and shade....

After climbing, he reflects: 

Upon the top of mountains, the air being subtle and pure, we respire with greater freedom, our bodies are more active, our minds more serene, our pleasures less ardent, and our passions much more moderate.  Our meditations acquire a degree of sublimity from the grandeur of the objects around us.  It seems as if, being lifted above all human society, we had left every low terrestrial sentiment behind.

He can find no words to express ’the amazing variety, magnitude, and beauty of a thousand stupendous objects, the pleasure of gazing at an entire new scene ... and beholding, as it were, another Nature and a new world.’

Earlier in the year he wrote his letters to Julia upon a block of stone in his favourite wild spot, and the wintry landscape harmonized with his feelings: 

I run to and fro, climb the rocks and explore my whole district, and find everything as horrible without as I experienced it within.  There is no longer any verdure to be seen, the grass is yellow and withered, the trees are stripped of their foliage, and the north-east blast heaps snow and ice around me.  In short, the whole face of Nature appears as decayed to my outward senses as I myself from within am dead to hope and joy.

Julia, too, is enthusiastic about places, where ’no vestiges are seen of human toil, no appearance of studied and laborious art; every object presents only a view of the tender care of Nature, our common mother.’

When St Preux knows that she returns his love, his sympathy for Nature overflows: 

I find the country more delightful, the verdure fresher and livelier, the air more temperate, and the sky more serene than ever I did before; even the feathered songsters seem to tune their tender throats with more harmony and pleasure; the murmuring rills invite to love-inspiring dalliance, while the blossoms of the vine regale me from afar with the choicest perfumes ... let us animate all Nature, which is absolutely dead without the genial warmth of love.

St Preux escorts his old love to the Meillerie, and it was with his description of this that Rousseau unrolled the full charm of mountain scenery, and opened the eyes of his readers to see it.