This area, which is situated on the edge of the city, gets its name from the color of a large part of its floor surface, notably on the eastern second level. This particularity adds to the rather joyful atmosphere, which predisposes the islet towards its adaptation as a zone for play. The different levels — three in the east, two in the west — are supported by a metal construction, disengaged from the ground. Titanium has been used for the construction bearing the floors and the buildings within; nylon for the walkways and to cover dividing- and partition-walls. The lightness of this construction explains not only the minimum use of supports, but also a great flexibility in the handling of the different parts, and the complete suppression of volumes. The metal structure may be considered as the basis for an arrangement of interchangeable, dismounted element-types and furniture, favoring the permanent variation of the environment. Thus the following description will restrict itself to the general framework of the arrangement. The structure consisting of superimposed levels means that the greater part of the surface must be illuminated and climatized artificially. Yet nowhere has it been sought to imitate natural conditions and forms of lighting. This becomes an integral part in the ambient games that are one of the attractions of the yellow zone. It should be noted, furthermore, that in many places one emerges suddenly into the open air.
One can arrive in this part of the city either by air, the terracing offering a series of landing strips; by car, at ground level; or lastly by underground train — according to the distances to be covered. Crossed in all directions by freeways, the ground level is devoid of buildings, with the exception of various pylons which support the construction, and a round building of six storeys (A), which supports the overhanging terrace. these supports, around which one has foreseen areas for the parking of the means of transport, contain the lifts which go up to the upper levels of the city or to the basement floors. The building (A) which houses the technical services, is separated from the rest of the islet and is only accessible from the terraces or the ground level. All the rest communicates internally and forms an expansive common space, except for only two buildings on the periphery of the city, containing apartments (B and C). Between these apartment buildings, whose windows look out onto the landscape, are to be found, at the north-east angle of the town and extending beyond the upper terraces, the great arrival hall (D) and a metal construction covered in sheet-aluminium of an extremely free form, whose two floors contain the passenger station and warehouses for the distribution of goods. While the hall is open to the air, the interior of the area itself is entirely covered. The eastern part is divided vertically into two covered floors, plus the part of the terracing for the aerodrome. By means of furniture acting as dividers, the floors are arranged into a great number of rooms — communicating horizontally as well as vertically, by means of stairs — whose varied ambiances are continually changed by situationist teams, in conjunction with the technical services. Intellectual games, above all, are practiced there.
The western part appears immediately more complicated. There are two labyrinth-houses, one large and one small (L and M), which take up and develop the ancient forces of architectural confusion: the water effects (G), the circus (H), the great ballroom (N), the white plaza (F) beneath which is suspended the green plaza, which enjoys a splendid view of the freeway traffic that passes below.
The two labyrinth-houses are formed by a great number of irregularly-shaped chambers, spiral staircases, distant corners, wastelands, cul-de-sacs. One goes through them adventurously. One can find oneself in a quiet room, clad in insulating material; the loud room with its vivid colors and ear-splitting sounds; the room of echoes (radiophonic speaker games); the room of images (cinematic games); the room for reflection (games of psychological resonance); the room for rest; the room for erotic games; the room of coincidences, etc. An extended stay in these houses has the tonic effect of a brainwashing and is frequently undertaken to erase the effects of habits.
The water games are found in the open air between these two houses, the terracing above having an opening which permits the sky to be seen. Jets of water and fountains are interspersed here with hoardings and constructions in bizarre shapes, including a heated grotto of glass where one can bathe in deepest winter while watching the stars.
By taking passage K, which instead of windows is equipped with large optical lenses that greatly magnify the view of the neighboring district, one arrives at the grand ballroom. Or instead one passes along the terraces around the water effects, which jut out over the white plaza, visible below, where demonstrations are held; and which also give access to the green plaza on the floor below. In descending below this plaza the public transport may be found which communicates with the other neighborhoods.
The yellow zone is the first itinerary in Promenades in New Babylon, a descriptive guide to the maquette-islets whose assembly constitutes a reduced model of the “covered city.” In #3 of this bulletin Constant formulated the basic principles of this particular hypothetical notion of unitary urbanism. [Another City for Another Life]