Pity, as it is well described in the text:
The effect was that of a Cyclopean city of no architecture known to man or to human imagination, with vast aggregations of night-black masonry embodying monstrous perversions of geometrical laws. There were truncated cones, sometimes terraced or fluted, surmounted by tall cylindrical shafts here and there bulbously enlarged and often capped with tiers of thinnish scalloped disks; and strange beetling, table-like constructions suggesting piles of multitudinous rectangular slabs or circular plates or five-pointed stars with each one overlapping the one beneath. There were composite cones and pyramids either alone or surmounting cylinders or cubes or flatter truncated cones and pyramids, and occasional needle-like spires in curious clusters of five. All of these febrile structures seemed knit together by tubular bridges crossing from one to the other at various dizzy heights, and the implied scale of the whole was terrifying and oppressive in its sheer gigantism.
http://en.wikisource.org/wiki/At_the_Mountains_of_Madness/Chapter_3Although that is the mirage, it seems fairly accurate:
Yet now the sway of reason seemed irrefutably shaken, for this Cyclopean maze of squared, curved, and angled blocks had features which cut off all comfortable refuge. It was, very clearly, the blasphemous city of the mirage in stark, objective, and ineluctable reality.
...
Of course the phantom had been twisted and exaggerated, and had contained things which the real source did not contain; yet now, as we saw that real source, we thought it even more hideous and menacing than its distant image.
...
The foothills were more sparsely sprinkled with grotesque stone structures, linking the terrible city to the already familiar cubes and ramparts which evidently formed its mountain outposts. These latter, as well as the queer cave-mouths, were as thick on the inner as on the outer sides of the mountains.
...
The nameless stone labyrinth consisted, for the most part, of walls from 10 to 150 feet in ice-clear height, and of a thickness varying from five to ten feet. It was composed mostly of prodigious blocks of dark primordial slate, schist, and sandstone—blocks in many cases as large as 4 × 6 × 8 feet—though in several places it seemed to be carved out of a solid, uneven bed-rock of pre-Cambrian slate. The buildings were far from equal in size; there being innumerable honeycomb-arrangements of enormous extent as well as smaller separate structures. The general shape of these things tended to be conical, pyramidal, or terraced; though there were many perfect cylinders, perfect cubes, clusters of cubes, and other rectangular forms, and a peculiar sprinkling of angled edifices whose five-pointed ground plan roughly suggested modern fortifications. The builders had made constant and expert use of the principle of the arch, and domes had probably existed in the city’s heyday.
http://en.wikisource.org/wiki/At_the_Mountains_of_Madness/Chapter_5Clearly the mention of cubes makes Cubism seems appropriate (especially for the cubes they initially see in the mountains), but I think Cubism would really come into its own when depicting R'lyeh:
Without knowing what futurism is like, Johansen achieved something very close to it when he spoke of the city; for instead of describing any definite structure or building, he dwells only on broad impressions of vast angles and stone surfaces—surfaces too great to belong to anything right or proper for this earth, and impious with horrible images and hieroglyphs. I mention his talk about angles because it suggests something Wilcox had told me of his awful dreams. He said that the geometry of the dream-place he saw was abnormal, non-Euclidean, and loathsomely redolent of spheres and dimensions apart from ours. Now an unlettered seaman felt the same thing whilst gazing at the terrible reality.
Johansen and his men landed at a sloping mud-bank on this monstrous Acropolis, and clambered slipperily up over titan oozy blocks which could have been no mortal staircase. The very sun of heaven seemed distorted when viewed through the polarising miasma welling out from this sea-soaked perversion, and twisted menace and suspense lurked leeringly in those crazily elusive angles of carven rock where a second glance showed concavity after the first showed convexity.
...
It was Rodriguez the Portuguese who climbed up the foot of the monolith and shouted of what he had found. The rest followed him, and looked curiously at the immense carved door with the now familiar squid-dragon bas-relief. It was, Johansen said, like a great barn-door; and they all felt that it was a door because of the ornate lintel, threshold, and jambs around it, though they could not decide whether it lay flat like a trap-door or slantwise like an outside cellar-door. As Wilcox would have said, the geometry of the place was all wrong. One could not be sure that the sea and the ground were horizontal, hence the relative position of everything else seemed phantasmally variable.
http://en.wikisource.org/wiki/The_Call_of_Cthulhu/Chapter_IIIInteresting that Lovecraft himself mentions
Futurism. Although it is later than Call of Cthulhu, I am reminded of "
Nose Dive on the City". Looking for that I found a page of
20 Dynamic Paintings From The Italian Futurists, which includes other paintings with disturbing geometries, like "The Street Enters the House", "Simultaneous Visions", "Burning City" and "Lightning Composer."
There are some good examples of post-WWII Futrist architecture, and the CLA Building in particular looks suitably... "jarring":
http://en.wikipedia.org/wiki/Futurist_architectureI suppose the irony in Lovecraft mentioning Futurism is that he had dubious views on race and the Italian Futurists would go on to largely support Mussolini and the fascists.
