After the famous fire of 64A.D., in which his house, the Domus Transitoria (Transitory House) was destroyed, he ordered the construction of the most fantastic imperial residence ever built in Rome.Nero, appropriated huge areas of central Rome for his proposed pleasure dome. The complex was eventually to spread over a quarter of the city, covering the Esquiline, Coelian and Palatine hills (today valley of the Colosseum).
Over a surface of 100 hectares alternated, as Svetonio says, porches and palaces, pavilions and baths (fed direct either by sea water or from sulphurous springs), gardens, pastures, vineyards and forests " full of domestic and wild animals of all species ".
Around the central pond, the architects in charge, Severo and Celere, erected buildings "so big as real towns ", adorned with hundred of statues sacked in Greece and Asia Minor, preceded by a 30mt statue of the emperor (called the " Colossus ", after which the Colosseum got its name ). What remained of the Domus was used as foundations for the Baths of Trajan. They consists of two wings with several rooms displayed around a rectangular courtyard. The most famous ones: the rooms to the south of the great peristyle, divided in two identical apartments with bedrooms, perhaps private residence of the imperial couple (" room of the yellow vault ", " room of the black vault", " room of the vault of the owls" and other symmetrical rooms); the hall that overlooks the polygonal court, with a famous decoration with gilded stuccoes and mythological scenes, badly preserved but famous for its Renaissance motifs (" room of the gilded vault "); the huge octagonal room, with nearly non- existent walls which led into other rooms. This room , together with the surrounding rooms in a radial disposition, constitutes one of the masterpieces of Roman architecture.
The decorations, in great part lost, are a work at least of two hands (one is perhaps of the famous Fabullo, skilful painter who painted wearing a toga). Some paintings are in the traditional style, with fine architectonic and fantastic elements that enclose small landscapes painted with rapid brush strokes. Others paintings present an innovation in the decorative system, widely articulated with the insertion of figures in the several sections (first example of " fourth style"). Nothing remains of the dining rooms with " ceilings composed of movable ivory tiles pierced with holes so that flowers or perfume could be sprinkled on the guests below" and even the columns, the coverings and the pavements in marble of the rooms have been removed and red-used for the Baths of Trajan. Discovered in the Renaissance, the Domus has been visited by many artists who where inspired by the decorative motifs of the frescoes (called "grotesque ") and who left their names scratched on the walls.