From the air, as Charles Cotton has put it, the central part of Otago appears as “a very roughly laid mosaic of enormous blocks with more or less rectilinear boundaries”. The “grand simplicity” of first impressions prove inexact upon detailed examination, but the unforgettable landscapes of Otago are truly composed of severe lines and blocks and planes; their stark geometry uninterrupted across extensive treeless plains and apparently limitless plateau. But whilst towards evening this landscape is chiaroscuro, in the full light of a clear winter's morning the colours are those of a Paul Nash landscape. Only a resort to hyperbole can convey the brilliance of the colours and the exact delineation of the forms. The autumn is especially beautiful. Climate, structure, vegetation, and man combine to produce this unique landscape. An extensive surface, from which most of the cover has been stripped to reveal the schist and old greywacke undermass, has been left as peneplain extending through eastern Otago from the Shag River to the Clutha. It is conspicuous on the journey from Middlemarch to Dunedin. In Central Otago the surface has been broken and uplifted to produce flat-topped block mountains, or ranges, with intervening basins. From the east to the west a succession of these landforms occur, commencing with the basis of the upper Taieri Plains (altitude, 1,200 ft), overlooked by the Rock and Pillar Range (summit, 4,755 ft), and followed by the Maniototo Plain (altitude, 1,500 ft), the Rough Ridge (summit, 3,859 ft), the Ida Valley (altitude, 1,500 ft), the Raggedy Blackstone Range (summit, 3,200 ft), the Manuherikia depression (altitude, 1,000 ft), the Dunstan Mountains (5,421 ft), and the valley of the Upper Clutha, which is dominated by the Pisa Range (summit, 6,327 ft). Immediately to the west a different set of erosional forces has produced the glaciated lake country, which attains its magnificence around the shores of Lake Wakatipu.