Ключевые слова: architecture, channel, collector, concrete, corridor, danger, dark, decay, deep, digger, dirty, drain, drainage, ecology, escape, exploration, exploring, flowing, geometric, industrial, inside, mud, passage, pipe, pipeline, pollution, rectangular, reflection, river, sewage, sewer, sewerage, stream, subterranean, town, tube, tubing, tunnel, underground, urban, waste, wastewater, water,