The Buildings of the City are generally high, baroque and dark. They are made of a black, hard and smooth material, not unlike plastic. The material, known only as "building material", is alive and can heal itself and regrow damaged parts. Actually, the buildings are not real buildings but growths from the City beneath. When a building starts to grow, long slender stalks of black material sprout straight upward into the air. Branches and girders grow between them and form a complex network outlining the building. The branches now start to grow smaller and smaller branches, slowly filling the building. Finally, they meld together into a seamless construction, and the building is ready to be used. There are seldom free areas where new buildings can grow unimpeded. Instead they start to sprout inside old and dying buildings. The tendrils grow through the husk of the old, and the branches start to absorb or reform the old building. The result is often a mixture between the two buildings, where incompatible elements have been joined together. Hallways lead into elevator shafts, windows looks into living spaces and rooms are placed inside rooms. This patching and regrowing have shaped many of the older buildings, turning them into strange and confusing labyrinths. The buildings generally have slightly organic forms, with smooth corners, curved corridors and arched doorways. Inside the walls, pipes/blood vessels pump nourishment, water and energy up into the building. The elevators are ovoid chambers which smoothly move up and down into the great shafts. The ceilings are held up by arched ribs, and in the walls there are small holes where symbiotic beings live. The symbionts clean up dirt, remove small items and repair damage. On the outside, and in many places inside the buildings, plants grow. These plants range from dense "grass" to fractal, treelike structures. These plants are almost completely black, and often move to intercept as much sunlight as possible. At dawn, the plants unfold and turn towards the sun. In the evening, they fold together. In the night, they glow with a cold, blue-green light illuminating the city outside. The plants inside provide light continuously, as long as they are not subjected to sunlight (when they switch to their seasonal rhythm). Some grow in dense, glowing rugs, other plants are individual or form covering on the walls. It is common to remove plants from unused buildings along with some of the underlying material, and then keep them as portable lights. The buildings in the City are generally more than 50 stories high, and much higher skyscrapers are common. There are many buildings reaching a kilometre in height. There are also the Megabuildings, titanic structures several kilometres high and across. Inside these millions people can live, and whole cultures have evolved inside some of them. However, like all buildings they will not survive for eternity, and will sooner or later start to die. The emigrations of fugitives from doomed Megabuildings have caused great disruptions in the past, not to mention the problems with the decaying structure. A decaying Megabuilding may take millennia to decay to the point there new buildings can grow out of the ruins. During this time, the ruins often become home for many strange and dangerous beings or desperate humans. Sometimes two buildings across the street grow bridges between them, providing easy access and sharing of energy and nourishment. In some areas this has happened so often that the buildings have more or less merged into a dense complex, stretching over many blocks. Some of these complex will even start to grow together into "mini-Megstructures". They are however even more labyrinthine than normal structures, and often quite unsuitable for living in. The Streets are narrow, made of smooth dark grey material not unlike the "building material". There are no sidewalks or lanes, just a single surface. Along many streets "movement strips" are placed. They are iridescent strips, which will move everything placed on them forward without moving themselves. In some streets there are even several parallel strips with different speeds. Unfortunately, in many places they have imperfections hindering travel; passengers have to look for telltale spots in the surface and jump over them in order not to trip. Since there is very little traffic, most travel is done by foot. There is also a train system, which runs throughout the city in a complex network. Under the street level is the Underworld. The Underworld is the part of the city where energy, waste, nourishment and information from the Upperworld is collected, refined and reused. If the Upperworld is hard to orient in, the Underworld is a nightmare. It consists of rooms, tunnels, channels and shafts built/grown seemingly without any plan. Inside great pipes the waste of millions are transported to structures turning it into nourishment for the City and its inhabitants. Tunnels connect chambers holding unknown devices and structures. Great halls stand empty, flanked by immovable statues. Dead parks wither in sunless darkness. Whole buildings seems to have sunk down into the Underworld and become part of it. Deeper down, the tunnels become less and less traversable for humans, filled with detritus, strange growths and hinders. Nobody has ever seen the roots of the City. The Monuments are strange. They are constructions which seems to retain their place and shape regardless of time. Normal buildings flourish, die and are replaced about every millennia. But the monument buildings do not change, no new buildings try to reshape them and they do not change form. Most are guarded by powerful gods or spirits, and often important places. A typical example is the Temples of the Dead, where the dead are received by the priests and sent down into the Underworld through the White Elevators. Another typical monument is the Pillar of Time, a transparent pillar several meters high. On its surface, a set of thin red lines imperceptibly creeps towards the apex over the span of several years, then turns the pillar opaque red for a few minutes, and then it clears, and the lines start to rise again.