vast subterranean fantasy metropolis carved deep inside colossal natural cavern, multi‑tiered vertical city built along cave rock walls, stacked terraced stone buildings, sprawling suspended stone arch‑bridges connecting different urban layers, huge stalactites and glowing crystal pillars interspersed within city blocks, underground luminous river winding through urban districts, bioluminescent fungi and crystalline ore providing ambient native illumination, active inhabited city, no ruins, small‑scale subordinate human silhouettes on walkways for scale, high‑angle establishing shot, oblique overlook, 35‑mm equivalent focal length, revealing immense cavern ceiling and deep spatial depth, soft diffused cavern mist, damp stone texture, natural subterranean ambient light, clear spatial hierarchy, readable layered urban structure, cinematic imaging, depth hierarchy, atmospheric volumetric haze